CN115428512A - Multi-link RTS and CTS transmissions - Google Patents

Abstract

In a wireless local area network system, a receiving multi-link device (MLD) may not send a CTS frame even if the receiving multi-link device receives an RTS frame via a second link, in a case where an STA operating via a first link is a TXOP responder.

Description

Multi-link RTS and CTS transmissions

Technical Field

The present specification relates to a method of transmitting Request To Send (RTS)/Clear To Send (CTS) in a wireless local area network system.

Background

Wireless network technologies may include various types of Wireless Local Area Networks (WLANs). For example, the IEEE802.11ax standard proposes an enhanced communication environment using Orthogonal Frequency Division Multiple Access (OFDMA) and a downlink multi-user multiple input multiple output (DL MU MIMO) scheme.

The present specification addresses technical features that may be used in new communication standards. For example, the new communication standard may be the very high throughput (EHT) standard currently being discussed. The EHT standard may use a newly proposed increased bandwidth, enhanced PHY layer protocol data unit (PPDU) structure, enhanced sequence, hybrid automatic repeat request (HARQ) scheme, and the like. The EHT standard may be referred to as the IEEE802.11be standard.

Disclosure of Invention

Technical scheme

A method performed by a transmitting apparatus in a Wireless Local Area Network (WLAN) system according to various embodiments may include technical features related to a channel access method using a plurality of links. In a method performed in a receiving multi-link device (MLD) of a WLAN system, the receiving MLD may include a first station and a second Station (STA). A first STA may operate on a first link and a second STA may operate on a second link. The first STA may be a transmission opportunity (TXOP) responder. The receiving MLD may receive a first Request To Send (RTS) frame on a second link. Based on the first STA being a TXOP responder, the receiving MLD may skip a Clear To Send (CTS) frame transmission for the first RTS frame. The receiving MLD may receive a Physical Protocol Data Unit (PPDU) on a second link.

Advantageous effects

According to the embodiments of the present specification, when non-STR MLD is performing reception through some links, a CTS frame is not transmitted even if an RTS frame is received through other links. When the CTS frame is transmitted while transmission is performed through some links other than the STR MLD, collision may occur. Therefore, collisions between links of non-STR MLD can be avoided according to embodiments of the present description.

Drawings

Fig. 1 shows an example of a transmitting device and/or a receiving device of the present specification.

Fig. 2 is a conceptual diagram illustrating the structure of a Wireless Local Area Network (WLAN).

Fig. 3 shows a general link establishment process.

Fig. 4 shows an example of a PPDU used in the IEEE standard.

Fig. 5 shows a layout of Resource Units (RUs) used in a frequency band of 20 MHz.

Fig. 6 shows a layout of RUs used in a frequency band of 40 MHz.

Fig. 7 shows a layout of RUs used in a frequency band of 80 MHz.

Fig. 8 shows a structure of the HE-SIG-B field.

Fig. 9 shows an example of allocating a plurality of user STAs to the same RU through the MU-MIMO scheme.

Fig. 10 illustrates UL-MU based operation.

Fig. 11 shows an example of a trigger frame.

Fig. 12 shows an example of a common information field of a trigger frame.

Fig. 13 shows an example of subfields included in the per-user information field.

Figure 14 depicts technical features of the UORA scheme.

Fig. 15 shows an example of channels used/supported/defined within the 2.4GHz band.

Fig. 16 shows an example of channels used/supported/defined within the 5GHz band.

Fig. 17 shows an example of channels used/supported/defined within the 6GHz band.

Fig. 18 shows an example of a PPDU used in the present specification.

Fig. 19 shows an example of a transmitting apparatus and/or a receiving apparatus of a modification of the present specification.

Fig. 20 shows an example of channel bonding.

Fig. 21 illustrates an embodiment of a multilink transmission method.

Fig. 22 illustrates an embodiment of inter-link interference.

Fig. 23 illustrates an embodiment of internal interference occurring in non-STR linkset.

Fig. 24 to 26 illustrate an embodiment of an RTS/CTS transmission method.

Fig. 27 to 29 show an embodiment of a trigger frame format.

Fig. 30 illustrates an embodiment of operations of receiving an MLD.

Fig. 31 illustrates an embodiment of an operation of transmitting an MLD.

Detailed Description

In the present specification, "a or B" may mean "a only", "B only", or "both a and B". In other words, in the present specification, "a or B" may be interpreted as "a and/or B". For example, in the present specification, "a, B, or C" may mean "a only", "B only", "C only", or "any combination of a, B, and C".

A slash (/) or a comma as used in this specification may indicate "and/or". For example, "A/B" may represent "A and/or B". Thus, "a/B" may mean "a only", "B only", or "both a and B". For example, "a, B, C" may represent "a, B, or C.

In the present specification, "at least one of a and B" may mean "a only", "B only", or "both a and B". In addition, in the present specification, the expression "at least one of a or B" or "at least one of a and/or B" may be interpreted as "at least one of a and B".

In addition, in the present specification, "at least one of a, B, and C" may mean "a only", "B only", "C only", or "any combination of a, B, and C". In addition, "at least one of a, B, or C" or "at least one of a, B, and/or C" may mean "at least one of a, B, and C".

In addition, parentheses used in the specification may mean "for example". Specifically, when indicated as "control information (EHT-signal)", it may mean that "EHT-signal" is proposed as an example of "control information". In other words, the "control information" of the present specification is not limited to the "EHT-signal", and the "EHT-signal" may be proposed as an example of the "control information". In addition, when "control information (i.e., EHT signal)" is indicated, it may also mean that "EHT signal" is proposed as an example of "control information".

Technical features that are separately described in one drawing of this specification may be separately implemented or may be implemented simultaneously.

The following examples of the present specification are applicable to various wireless communication systems. For example, the following examples of the present specification may be applied to a Wireless Local Area Network (WLAN) system. For example, the description may apply to the IEEE802.11 a/g/n/ac standard or the IEEE802.11ax standard. In addition, the present specification is also applicable to a newly proposed EHT standard or IEEE802.11be standard. Furthermore, the examples of the present specification are also applicable to a new WLAN standard enhanced from the EHT standard or the IEEE802.11be standard. In addition, the examples of the present specification are applicable to a mobile communication system. For example, it is applicable to a mobile communication system based on Long Term Evolution (LTE) depending on a3 rd generation partnership project (3 GPP) standard and LTE-based evolution. In addition, the examples of the present specification are applicable to a communication system based on the 5G NR standard of the 3GPP standard.

Hereinafter, in order to describe technical features of the present specification, technical features applicable to the present specification will be described.

Fig. 1 shows an example of a transmitting device and/or a receiving device of the present specification.

In the example of fig. 1, various technical features described below may be performed. Fig. 1 relates to at least one Station (STA). For example, STAs 110 and 120 of the present specification may also be referred to by various terms such as mobile terminal, wireless device, wireless transmit/receive unit (WTRU), user Equipment (UE), mobile Station (MS), mobile subscriber unit, or simply user. STAs 110 and 120 of the present specification may also be referred to by various terms such as network, base station, node B, access Point (AP), repeater, router, repeater, and the like. The STAs 110 and 120 of the present specification may also be referred to by various names such as a receiving device, a transmitting device, a receiving STA, a transmitting STA, a receiving apparatus, a transmitting apparatus, and the like.

For example, STAs 110 and 120 may function as APs or non-APs. That is, STAs 110 and 120 of the present specification may function as APs and/or non-APs.

In addition to the IEEE802.11 standard, STAs 110 and 120 of the present specification may together support various communication standards. For example, communication standards based on 3GPP standards (e.g., LTE-a, 5G NR standards), etc. may be supported. In addition, the STA of the present specification may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, and the like. In addition, the STA of the present specification may support communication for various communication services such as voice call, video call, data communication, and self-driving (autonomous driving).

STAs 110 and 120 of the present specification may include a Medium Access Control (MAC) compliant with the IEEE802.11 standard and a physical layer interface for a radio medium.

STAs 110 and 120 will be described below with reference to sub-diagram (a) of fig. 1.

The first STA 110 may include a processor 111, a memory 112, and a transceiver 113. The processor, memory, and transceiver shown may be implemented separately as separate chips, or at least two blocks/functions may be implemented by a single chip.

The transceiver 113 of the first STA performs a signal transmission/reception operation. Specifically, IEEE802.11 packets (e.g., IEEE802.11 a/b/g/n/ac/ax/be, etc.) may be transmitted/received.

For example, first STA 110 may perform operations expected by an AP. For example, processor 111 of the AP may receive signals via transceiver 113, process Receive (RX) signals, generate Transmit (TX) signals, and provide control for signal transmission. The memory 112 of the AP may store signals (e.g., RX signals) received through the transceiver 113 and may store signals (e.g., TX signals) to be transmitted through the transceiver.

For example, the second STA120 may perform operations that are not expected by the AP STA. For example, the transceiver 123 of the non-AP performs a signal transmission/reception operation. Specifically, IEEE802.11 packets (e.g., IEEE802.11 a/b/g/n/ac/ax/be packets, etc.) may be transmitted/received.

For example, processor 121 of the non-AP STA may receive signals through transceiver 123, process RX signals, generate TX signals, and provide control for signal transmission. The memory 122 of the non-AP STA may store signals (e.g., RX signals) received through the transceiver 123 and may store signals (e.g., TX signals) to be transmitted through the transceiver.

For example, the operation of the device indicated as an AP in the description described below may be performed in the first STA 110 or the second STA120. For example, if the first STA 110 is an AP, the operation of the device indicated as an AP may be controlled by the processor 111 of the first STA 110, and the related signal may be transmitted or received through the transceiver 113 controlled by the processor 111 of the first STA 110. In addition, control information related to the operation of the AP or TX/RX signals of the AP may be stored in the memory 112 of the first STA 110. In addition, if the second STA120 is an AP, the operation of the device indicated as the AP may be controlled by the processor 121 of the second STA120, and the related signal may be transmitted or received through the transceiver 123 controlled by the processor 121 of the second STA120. In addition, control information related to the operation of the AP or TX/RX signals of the AP may be stored in the memory 122 of the second STA120.

For example, in the description described below, the operation of the device indicated as a non-AP (or user STA) may be performed in the first STA 110 or the second STA120. For example, if the second STA120 is a non-AP, the operation of the device indicated as a non-AP may be controlled by the processor 121 of the second STA120, and the related signal may be transmitted or received through the transceiver 123 controlled by the processor 121 of the second STA120. In addition, control information related to the operation of the non-AP or TX/RX signals of the non-AP may be stored in the memory 122 of the second STA120. For example, if the first STA 110 is a non-AP, the operation of the device indicated as a non-AP may be controlled by the processor 111 of the first STA 110, and the related signal may be transmitted or received through the transceiver 113 controlled by the processor 111 of the first STA 110. In addition, control information related to the operation of the non-AP or TX/RX signals of the non-AP may be stored in the memory 112 of the first STA 110.

In the description described below, devices referred to as a (transmission/reception) STA, a first STA, a second STA, STA1, STA2, AP, a first AP, a second AP, AP1, AP2, a (transmission/reception) terminal, a (transmission/reception) device, a (transmission/reception) apparatus, a network, and the like may mean the STAs 110 and 120 of fig. 1. For example, devices indicated as (but not specifically numbered) STAs, first STAs, second STAs, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmit/receive) terminals, (transmit/receive) devices, networks, and the like may mean the STAs 110 and 120 of fig. 1. For example, in the following example, operations of various STAs to transmit/receive a signal (e.g., PPDU) may be performed in the transceivers 113 and 123 of fig. 1. In addition, in the following example, operations of various STAs to generate TX/RX signals or to perform data processing and calculation in advance for the TX/RX signals may be performed in the processors 111 and 121 of fig. 1. For example, examples of operations for generating TX/RX signals or performing data processing and calculations in advance may include: 1) An operation of determining/obtaining/configuring/calculating/decoding/encoding bit information of subfields (SIG, STF, LTF, data) included in the PPDU; 2) An operation of determining/configuring/obtaining time resources or frequency resources (e.g., subcarrier resources) or the like for subfields (SIG, STF, LTF, data) included in the PPDU; 3) An operation of determining/configuring/obtaining a specific sequence (e.g., a pilot sequence, an STF/LTF sequence, an additional sequence applied to SIG) for a sub-field (SIG, STF, LTF, data) field included in the PPDU, or the like; 4) Power control operations and/or power saving operations applied to the STA; and 5) operations related to determination/acquisition/configuration/decoding/encoding, etc. of the ACK signal. Additionally, in the following examples, various information (e.g., information related to fields/subfields/control fields/parameters/power, etc.) used by various STAs to determine/obtain/configure/calculate/decode TX/RX signals may be stored in memories 112 and 122 of fig. 1.

The aforementioned devices/STAs of sub-diagram (a) of fig. 1 may be modified as shown in sub-diagram (b) of fig. 1. Hereinafter, the STA 110 and the STA120 of the present specification will be described based on sub-diagram (b) of fig. 1.

For example, the transceivers 113 and 123 shown in sub-figure (b) of fig. 1 may perform the same functions as the aforementioned transceivers shown in sub-figure (a) of fig. 1. For example, the processing chips 114 and 124 shown in sub-diagram (b) of fig. 1 may include processors 111 and 121 and memories 112 and 122. The processors 111 and 121 and the memories 112 and 122 shown in sub-diagram (b) of fig. 1 may perform the same functions as the aforementioned processors 111 and 121 and memories 112 and 122 shown in sub-diagram (a) of fig. 1.

The mobile terminal, wireless device, wireless transmit/receive unit (WTRU), user Equipment (UE), mobile Station (MS), mobile subscriber unit, user STA, network, base station, node B, access Point (AP), repeater, router, relay, receive unit, transmit unit, receive STA, transmit STA, receive device, transmit device, receive device, and/or transmit device described below may mean the STAs 110 and 120 shown in sub-diagram (a)/(B) of fig. 1, or may mean the processing chips 114 and 124 shown in sub-diagram (B) of fig. 1. That is, the technical features of the present specification may be performed in the STAs 110 and 120 shown in sub-diagram (a)/(b) of fig. 1, or the transceivers 113 and 123 shown in sub-diagram (a)/(b) of fig. 1 may be performed only in the processing chips 114 and 124 shown in sub-diagram (b) of fig. 1. For example, a technical feature of the transmitting STA transmitting the control signal may be understood as a technical feature of transmitting the control signal generated in the processors 111 and 121 illustrated in the subgraph (a)/(b) of fig. 1 through the transceiver 113 illustrated in the subgraph (a)/(b) of fig. 1. Alternatively, technical features of the transmitting STA transmitting the control signal may be understood as technical features of generating the control signal to be transmitted to the transceivers 113 and 123 in the processing chips 114 and 124 shown in sub-diagram (b) of fig. 1.

For example, the technical feature that the receiving STA receives the control signal may be understood as the technical feature that the control signal is received through the transceivers 113 and 123 shown in sub-diagram (a) of fig. 1. Alternatively, the technical feature that the receiving STA receives the control signal may be understood as the technical feature that the control signal received in the transceivers 113 and 123 shown in sub-diagram (a) of fig. 1 is obtained by the processors 111 and 121 shown in sub-diagram (a) of fig. 1. Alternatively, the technical feature that the receiving STA receives the control signal may be understood as the technical feature that the control signal received in the transceivers 113 and 123 shown in sub-diagram (b) of fig. 1 is obtained by the processing chips 114 and 124 shown in sub-diagram (b) of fig. 1.

Referring to sub-diagram (b) of fig. 1, software codes 115 and 125 may be included in memories 112 and 122. Software codes 115 and 126 may include instructions for controlling the operation of processors 111 and 121. Software codes 115 and 125 may be included as various programming languages.

The processors 111 and 121 or processing chips 114 and 124 of fig. 1 may include Application Specific Integrated Circuits (ASICs), other chipsets, logic circuits, and/or data processing devices. The processor may be an Application Processor (AP). For example, the processors 111 and 121 or the processing chips 114 and 124 of fig. 1 may include at least one of: a Digital Signal Processor (DSP), a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), and a modulator and demodulator (modem). For example, the processors 111 and 121 or the processing chips 114 and 124 of FIG. 1 may be composed of

Manufactured snappdagontm processor family, manufactured by

Series of EXYNOSS processors manufactured by

Series of processors made of

Family of HELIOTM processors made of

Manufactured ATOM processor family orProcessors enhanced from these processors.

In this specification, the uplink may mean a link for communication from the non-AP STA to the SP STA, and uplink PPDU/packet/signal or the like may be transmitted through the uplink. In addition, in this specification, downlink may mean a link for communication from an AP STA to a non-AP STA, and downlink PPDU/packet/signal or the like may be transmitted through the downlink.

Fig. 2 is a conceptual diagram illustrating the structure of a Wireless Local Area Network (WLAN).

The upper part of fig. 2 shows the structure of an infrastructure Basic Service Set (BSS) of Institute of Electrical and Electronics Engineers (IEEE) 802.11.

Referring to the upper part of fig. 2, the wireless LAN system may include one or more infrastructure BSSs 200 and 205 (hereinafter, referred to as BSSs). BSSs 200 and 205, which are sets of an AP and an STA (e.g., access Point (AP) 225 and station (STA 1) 200-1) successfully synchronized to communicate with each other, are not concepts indicating a specific area. BSS 205 may include one or more STAs 205-1 and 205-2 that may join an AP 230.

The BSS may include at least one STA, an AP providing distributed services, and a Distribution System (DS) 210 connecting a plurality of APs.

The distribution system 210 may implement an Extended Service Set (ESS) 240 extended by connecting a plurality of BSSs 200 and 205. ESS 240 may be used as a term indicating one network configured by connecting one or more APs 225 or 230 via the distribution system 210. APs included in one ESS 240 may have the same Service Set Identification (SSID).

The portal 220 may serve as a bridge connecting a wireless LAN network (IEEE 802.11) and another network (e.g., 802.x).

In the BSS shown in the upper portion of fig. 2, a network between APs 225 and 230 and STAs 200-1, 205-1 and 205-2 may be implemented. However, the network is configured between the STAs to perform communication even without the APs 225 and 230. A network that performs communication by configuring a network between STAs even without the APs 225 and 230 is defined as an ad hoc network or an Independent Basic Service Set (IBSS).

The lower part of fig. 2 shows a conceptual diagram illustrating IBSS.

Referring to the lower part of fig. 2, the IBSS is a BSS operating in an ad hoc mode. Since the IBSS does not include an Access Point (AP), there is no centralized management entity that performs a management function in the center. That is, in the IBSS, the STAs 250-1, 250-2, 250-3, 255-4 and 255-5 are managed in a distributed manner. In an IBSS, all STAs 250-1, 250-2, 250-3, 255-4, and 255-5 may be constituted by mobile STAs and access to the DS is not allowed to constitute a self-contained network.

Fig. 3 shows a general link establishment process.

In S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order to access the network, the STA needs to discover the participating network. The process by which a STA needs to identify a compatible network before joining a wireless network, and identifying the networks present in a particular area is called scanning. The scanning method comprises active scanning and passive scanning.

Fig. 3 illustrates a network discovery operation including an active scanning process. In the active scanning, an STA performing scanning transmits a probe request frame and waits for a response to the probe request frame in order to identify which AP exists around while moving to a channel. The responder transmits a probe response frame as a response to the probe request frame to the STA that has transmitted the probe request frame. Here, the responder may be an STA that transmits the last beacon frame in the BSS of the channel being scanned. In the BSS, the AP is a responder since the AP transmits a beacon frame. In the IBSS, since STAs in the IBSS take turns transmitting beacon frames, the responder is not fixed. For example, when an STA transmits a probe request frame via channel 1 and receives a probe response frame via channel 1, the STA may store BSS-related information included in the received probe response frame, may move to a next channel (e.g., channel 2), and may perform scanning (e.g., transmitting a probe request and receiving a probe response via channel 2) in the same method.

Although not shown in fig. 3, the scanning may be performed by a passive scanning method. In passive scanning, an STA performing scanning may wait for a beacon frame while moving to a channel. The beacon frame is one of management frames in IEEE802.11, and is periodically transmitted to indicate the presence of a wireless network and enable an STA performing scanning to find and join the wireless network. In the BSS, the AP is configured to periodically transmit a beacon frame. In the IBSS, STAs in the IBSS take turns transmitting beacon frames. Upon receiving the beacon frame, the STA performing the scanning stores information about the BSS included in the beacon frame and records beacon frame information in the respective channels while moving to another channel. The STA that receives the beacon frame may store the BSS-related information included in the received beacon frame, may move to a next channel, and may perform scanning in the next channel in the same manner.

After discovering the network, the STA may perform an authentication process in S320. This authentication process may be referred to as a first authentication process to clearly distinguish from the security establishment operation in subsequent S340. The authentication process in S320 may include a process in which the STA transmits an authentication request frame to the AP and the AP transmits an authentication response frame to the STA in response. The authentication frame used for the authentication request/response is a management frame.

The authentication frame may include information related to an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a limited round-robin group.

The STA may send an authentication request frame to the AP. The AP may determine whether to allow authentication of the STA based on information included in the received authentication request frame. The AP may provide the authentication process result to the STA via the authentication response frame.

When the STA is successfully authenticated, the STA may perform an association process in S330. The association process includes a process in which the STA transmits an association request frame to the AP and the AP transmits an association response frame to the STA in response. For example, the association request frame may include information related to various capabilities, beacon listening intervals, service Set Identifiers (SSIDs), supported rates, supported channels, RSNs, mobility domains, supported operation classes, traffic Indication Map (TIM) broadcast requests, and interworking service capabilities. For example, the association response frame may include information related to various capabilities, status codes, association IDs (AIDs), supported rates, enhanced Distributed Channel Access (EDCA) parameter sets, received Channel Power Indicators (RCPIs), received signal-to-noise indicators (RSNIs), mobility domains, time out intervals (association recovery times), overlapping BSS scanning parameters, TIM broadcast responses, and QoS maps.

In S340, the STA may perform a security setup process. The security establishment process in S340 may include a process of establishing a private key through a four-way handshake (e.g., through an Extensible Authentication Protocol Over LAN (EAPOL) frame).

Fig. 4 shows an example of a PPDU used in the IEEE standard.

As shown, various types of PHY Protocol Data Units (PPDUs) are used in the IEEE a/g/n/ac standard. Ext> specificallyext>,ext> theext> LTFext> andext> STFext> includeext> trainingext> signalsext>,ext> SIGext> -ext> aext> andext> SIGext> -ext> bext> includeext> controlext> informationext> forext> aext> receivingext> staext>,ext> andext> theext> dataext> fieldext> includesext> userext> dataext> correspondingext> toext> aext> psduext> (ext> macext> pduext> /ext> aggregateext> macext> pduext>)ext>.ext>

FIG. 4 also shows an example of an HE PPDU according to IEEE802.11 ax. The HE PPDU according to fig. 4 is an exemplary PPDU for multiple users. The HE-SIG-B may be included only in PPDUs for multiple users, and may be omitted in PPDUs for a single user.

As shown in fig. 4, the HE-PPDU for Multiple Users (MUs) may include a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal (L-SIG), a high efficiency signal a (HE-SIG a), a high efficiency signal B (HE-SIG B), a high efficiency short training field (HE-STF), a high efficiency long training field (HE-LTF), a data field (alternatively, a MAC payload), and a Packet Extension (PE) field. Each field may be sent within the time period shown (i.e., 4 or 8 mus).

Hereinafter, a Resource Unit (RU) for PPDU is described. An RU may include multiple subcarriers (or tones). The RU may be used to transmit signals to a plurality of STAs according to OFDMA. Further, an RU may also be defined as transmitting a signal to one STA. RUs may be used for STFs, LTFs, data fields, etc.

Fig. 5 shows a layout of Resource Units (RUs) used in a frequency band of 20 MHz.

As shown in fig. 5, resource Units (RUs) corresponding to different numbers of tones (i.e., subcarriers) may be used to form some fields of the HE-PPDU. For example, resources may be allocated for the HE-STF, HE-LTF, and data fields in the illustrated RUs.

As shown in the uppermost part of fig. 5, 26 units (i.e., units corresponding to 26 tones) may be provided. Six tones may be used for the guard band in the leftmost band of the 20MHz band and five tones may be used for the guard band in the rightmost band of the 20MHz band. Further, seven DC tones may be inserted in the center frequency band (i.e., the DC frequency band), and 26 units corresponding to 13 tones of each of the left and right sides of the DC frequency band may be provided. The 26 units, 52 units, and 106 units may be allocated to other frequency bands. Respective units may be allocated to a receiving STA (i.e., a user).

The layout of RUs in fig. 5 may be used not only for Multiple Users (MUs), but also for a Single User (SU), in which case one 242 unit may be used and three DC tones may be inserted, as shown in the lowest part of fig. 5.

Although FIG. 5 proposes RUs having various sizes, i.e., 26-RU, 52-RU, 106-RU, and 242-RU, a particular size of RU may be extended or increased. Therefore, the present embodiment is not limited to each RU of a specific size (i.e., the number of corresponding tones).

Fig. 6 shows a layout of RUs used in a frequency band of 40 MHz.

Similar to FIG. 5, which uses RUs of various sizes, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. may be used in the example of FIG. 6. Further, five DC tones may be inserted in the center frequency, 12 tones may be used for the guard band in the leftmost band of the 40MHz band, and 11 tones may be used for the guard band in the rightmost band of the 40MHz band.

As shown in fig. 6, when the layout of RUs is for a single user, 484-RU may be used. The specific number of RUs may vary similar to fig. 5.

Fig. 7 shows a layout of RUs used in a frequency band of 80 MHz.

Similar to FIGS. 5 and 6, which use RUs of various sizes, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. may be used in the example of FIG. 7. Furthermore, seven DC tones may be inserted in the center frequency, 12 tones may be used for the guard band in the leftmost band of the 80MHz band, and 11 tones may be used for the guard band in the rightmost band of the 80MHz band. In addition, 26-RU corresponding to 13 tones on each of the left and right sides of the DC band may be used.

As shown in fig. 7, when the layout of RU is for a single user, 996-RU may be used, in which case five DC tones may be inserted.

The RU described in this specification may be used in Uplink (UL) communication and Downlink (DL) communication. For example, when performing UL-MU communications requested through a trigger frame, a transmitting STA (e.g., an AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA and may allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA through the trigger frame. Thereafter, the first STA may transmit a first trigger-based PPDU based on the first RU, and the second STA may transmit a second trigger-based PPDU based on the second RU. The first/second trigger-based PPDUs are transmitted to the AP at the same (or overlapping) time period.

For example, when configuring a DL MU PPDU, a transmitting STA (e.g., an AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA and may allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA. That is, a transmitting STA (e.g., an AP) may transmit HE-STF, HE-LTF, and Data fields for the first STA through a first RU in one MU PPDU, and may transmit HE-STF, HE-LTF, and Data fields for a second STA through a second RU.

Information about the layout of RUs may be signaled through HE-SIG-B.

Fig. 8 shows a structure of the HE-SIG-B field.

As shown, the HE-SIG-B field 810 includes a common field 820 and a user-specific field 830. The common field 820 may include information commonly applied to all users receiving SIG-B (i.e., user STAs). The user-specific field 830 may be referred to as a user-specific control field. When SIG-B is transmitted to multiple users, the user-specific field 830 may apply only to any one of the multiple users.

As shown in fig. 8, the common field 820 and the user-specific field 830 may be encoded separately.

The common field 820 may include N × 8 bits of RU allocation information. For example, the RU allocation information may include information related to a location of the RU. For example, when a 20MHz channel is used as shown in fig. 5, the RU allocation information may include information on a specific frequency band in which a specific RU (26-RU/52-RU/106-RU) is arranged.

An example of the case where the RU allocation information consists of 8 bits is as follows.

[ Table 1]

As shown in the example of fig. 5, up to nine 26-RUs may be allocated to a 20MHz channel. When the RU allocation information of the common field 820 is set to "00000000" as shown in table 1, nine 26-RUs may be allocated to the corresponding channel (i.e., 20 MHz). In addition, when the RU allocation information of the common field 820 is set to "00000001" as shown in table 1, seven 26-RUs and one 52-RU are arranged in the corresponding channel. That is, in the example of FIG. 5, the rightmost side may be assigned 52-RUs, and the left side thereof may be assigned seven 26-RUs.

The example of table 1 shows only some RU locations that are capable of displaying RU allocation information.

For example, the RU allocation information may include the example of table 2 below.

[ Table 2]

"01000y2y1y0" refers to an example where 106-RUs are allocated to the leftmost side of a 20MHz channel, and five 26-RUs are allocated to the right side thereof. In this case, a plurality of STAs (e.g., user STAs) may be allocated to 106-RUs based on the MU-MIMO scheme. Specifically, up to 8 STAs (e.g., user STAs) may be allocated to the 106-RU, and the number of STAs (e.g., user STAs) allocated to the 106-RU is determined based on the 3-bit information (y 2y1y 0). For example, when 3-bit information (y 2y1y 0) is set to N, the number of STAs (e.g., user STAs) allocated to 106-RU based on the MU-MIMO scheme may be N +1.

In general, a plurality of STAs (e.g., user STAs) different from each other may be allocated to a plurality of RUs. However, a plurality of STAs (e.g., user STAs) may be allocated to one or more RUs having at least a specific size (e.g., 106 subcarriers) based on the MU-MIMO scheme.

As shown in fig. 8, the user-specific field 830 may include a plurality of user fields. As described above, the number of STAs (e.g., user STAs) allocated to a specific channel may be determined based on the RU allocation information of the common field 820. For example, when the RU allocation information of the common field 820 is "00000000", one user STA may be allocated to each of the nine 26-RUs (e.g., nine user STAs may be allocated). That is, up to 9 user STAs may be allocated to a specific channel through the OFDMA scheme. In other words, up to 9 user STAs may be allocated to a specific channel through a non-MU-MIMO scheme.

For example, when the RU allocation is set to "01000y2y1y0", a plurality of STAs may be allocated to 106-RUs disposed at the leftmost side by the MU-MIMO scheme, and five user STAs may be allocated to five 26-RUs disposed at the right side thereof by the non-MU-MIMO scheme. This situation is illustrated by the example of fig. 9.

Fig. 9 shows an example of allocating a plurality of user STAs to the same RU through the MU-MIMO scheme.

For example, when the RU allocation is set to "01000010" as shown in FIG. 9, 106-RUs may be allocated to the leftmost side of a particular channel and five 26-RUs may be allocated to the right side thereof. In addition, three user STAs may be allocated to 106-RUs through the MU-MIMO scheme. As a result, since eight user STAs are allocated, the user-specific field 830 of the HE-SIG-B may include eight user fields.

The eight user fields may be represented in the order shown in fig. 9. In addition, as shown in fig. 8, two user fields may be implemented using one user block field.

The user fields shown in fig. 8 and 9 may be configured based on two formats. That is, user fields related to the MU-MIMO scheme may be configured in a first format, and user fields related to the non-MIMO scheme may be configured in a second format. Referring to the example of fig. 9, the user fields 1 to 3 may be based on a first format, and the user fields 4 to 8 may be based on a second format. The first format or the second format may include bit information of the same length (e.g., 21 bits).

Each user field may have the same size (e.g., 21 bits). For example, the user field of the first format (first MU-MIMO scheme) may be configured as follows.

For example, the first bit (i.e., B0-B10) of the user field (i.e., 21 bits) may include identification information (e.g., STA-ID, partial AID, etc.) of the user STA allocated the corresponding user field. In addition, the second bit (i.e., B11-B14) in the user field (i.e., 21 bits) may include information related to the spatial configuration. Specifically, examples of the second bit (i.e., B11-B14) may be as shown in tables 3 and 4 below.

[ Table 3]

[ Table 4]

As shown in table 3 and/or table 4, the second bit (e.g., B11-B14) may include information on the number of spatial streams allocated to the plurality of user STAs allocated based on the MU-MIMO scheme. For example, when three user STAs are allocated to 106-RUs based on the MU-MIMO scheme as shown in fig. 9, N _ user is set to "3". Thus, the values of N _ STS [1], N _ STS [2] and N _ STS [3] can be determined as shown in Table 3. For example, when the value of the second bit (B11-B14) is "0011", it may be set to N _ STS [1] =4, N _ STS [2] =1, N _ STS [3] =1. That is, in the example of fig. 9, four spatial streams may be allocated to the user field 1, one spatial stream may be allocated to the user field 1, and one spatial stream may be allocated to the user field 3.

As shown in the examples of table 3 and/or table 4, the information (i.e., the second bit, B11-B14) regarding the number of spatial streams for the user STA may consist of 4 bits. In addition, information on the number of spatial streams for the user STA (i.e., the second bit, B11-B14) may support up to eight spatial streams. In addition, information on the number of spatial streams for the user STA (i.e., the second bit, B11-B14) may support one user STA up to four spatial streams.

In addition, the third bit (i.e., B15-18) in the user field (i.e., 21 bits) may include Modulation and Coding Scheme (MCS) information. The MCS information may be applied to a data field in a PPDU including the corresponding SIG-B.

The MCS, MCS information, MCS index, MCS field, and the like used in this specification may be indicated by an index value. For example, the MCS information may be indicated by index 0 to index 11. The MCS information can include information related to constellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.) and information related to coding rate (e.g., 1/2, 2/3, 3/4, 5/6e, etc.). Information on a channel coding type (e.g., LCC or LDPC) may not be included in the MCS information.

In addition, a fourth bit (i.e., B19) in the user field (i.e., 21 bits) may be a reserved field.

In addition, the fifth bit (i.e., B20) in the user field (i.e., 21 bits) may include information on a coding type (e.g., BCC or LDPC). That is, the fifth bit (i.e., B20) may include information on a type of channel coding (e.g., BCC or LDPC) applied to a data field in a PPDU including the corresponding SIG-B.

The above examples relate to a user field of a first format (format of MU-MIMO scheme). An example of the user field of the second format (format other than the MU-MIMO scheme) is as follows.

The first bit (e.g., B0-B10) in the user field of the second format may include identification information of the user STA. In addition, a second bit (e.g., B11-B13) in the user field of the second format may include information on the number of spatial streams applied to the corresponding RU. In addition, a third bit (e.g., B14) in the user field of the second format may include information on whether the beamforming steering matrix is applied. The fourth bit (e.g., B15-B18) in the user field of the second format may include Modulation and Coding Scheme (MCS) information. In addition, a fifth bit (e.g., B19) in the user field of the second format may include information on whether Dual Carrier Modulation (DCM) is applied. In addition, the sixth bit (i.e., B20) in the user field of the second format may include information on a coding type (e.g., BCC or LDPC).

Fig. 10 illustrates UL-MU based operation. As shown, a transmitting STA (e.g., an AP) may perform channel access through contention (e.g., a backoff operation), and may transmit a trigger frame 1030. That is, the transmitting STA may transmit a PPDU including the trigger frame 1030. Upon receiving the PPDU including the trigger frame, a Trigger Based (TB) PPDU is transmitted after a delay corresponding to the SIFS.

The TB PPDUs 1041 and 1042 may be transmitted at the same time period and may be transmitted from a plurality of STAs (e.g., user STAs) having AIDs indicated in the trigger frame 1030. The ACK frame 1050 for the TB PPDU may be implemented in various forms.

Specific features of the trigger frame are described with reference to fig. 11 to 13. Even if UL-MU communication is used, an Orthogonal Frequency Division Multiple Access (OFDMA) scheme or a MU MIMO scheme may be used, and the OFDMA and MU-MIMO schemes may be simultaneously used.

Fig. 11 shows an example of a trigger frame. The trigger frame of fig. 11 allocates resources for uplink multi-user (MU) transmissions and may be sent, for example, from an AP. The trigger frame may be configured by a MAC frame and may be included in a PPDU.

Various fields shown in fig. 11 may be partially omitted, and another field may be added. In addition, the length of each field may be changed differently from that shown in the figure.

The frame control field 1110 of fig. 11 may include information on a MAC protocol version and additional control information. The duration field 1120 may include NAV-configured time information or information related to an identifier (e.g., AID) of the STA.

In addition, the RA field 1130 may include address information of a receiving STA corresponding to the trigger frame, and may optionally be omitted. The TA field 1140 may include address information of an STA (e.g., an AP) that transmits a corresponding trigger frame. The common information field 1150 includes common control information applied to a receiving STA that receives a corresponding trigger frame. Ext>ext> forext>ext> exampleext>ext>,ext>ext> aext>ext> fieldext>ext> indicatingext>ext> theext>ext> lengthext>ext> ofext>ext> anext>ext> Lext>ext> -ext>ext> SIGext>ext> fieldext>ext> ofext>ext> anext>ext> uplinkext>ext> PPDUext>ext> transmittedext>ext> inext>ext> responseext>ext> toext>ext> aext>ext> correspondingext>ext> triggerext>ext> frameext>ext> orext>ext> informationext>ext> forext>ext> controllingext>ext> theext>ext> contentext>ext> ofext>ext> aext>ext> SIGext>ext> -ext>ext> aext>ext> fieldext>ext> (ext>ext> i.e.ext>ext>,ext>ext> anext>ext> heext>ext> -ext>ext> SIGext>ext> -ext>ext> aext>ext> fieldext>ext>)ext>ext> ofext>ext> theext>ext> uplinkext>ext> PPDUext>ext> transmittedext>ext> inext>ext> responseext>ext> toext>ext> theext>ext> correspondingext>ext> triggerext>ext> frameext>ext> mayext>ext> beext>ext> includedext>ext>.ext>ext> In addition, as the common control information, information on the length of a CP of an uplink PPDU transmitted in response to a corresponding trigger frame or information on the length of an LTF field may be included.

In addition, it is preferable to include per-user information fields 1160#1 to 1160# n corresponding to the number of receiving STAs which receive the trigger frame of fig. 11. The per-user information field may also be referred to as an "assignment field".

In addition, the trigger frame of fig. 11 may include a padding field 1170 and a frame check sequence field 1180.

Each of the per-user information fields 1160#1 to 1160# n shown in fig. 11 may include a plurality of subfields.

Fig. 12 shows an example of a common information field of a trigger frame. The subfields of fig. 12 may be partially omitted, and additional subfields may be added. In addition, the length of the individual subfields shown may vary.

The shown length field 1210 has the same value as a length field of an L-SIG field of an uplink PPDU transmitted in response to a corresponding trigger frame, and the length field of the L-SIG field of the uplink PPDU indicates the length of the uplink PPDU. As a result, the length field 1210 of the trigger frame may be used to indicate the length of the corresponding uplink PPDU.

In addition, the concatenation identifier field 1220 indicates whether to perform a concatenation operation. The concatenated operation means that downlink MU transmissions and uplink MU transmissions are performed together in the same TXOP. That is, it means that downlink MU transmission is performed, after which uplink MU transmission is performed after a preset time (e.g., SIFS). During the tandem operation, only one transmitting device (e.g., AP) may perform downlink communication and multiple transmitting devices (e.g., non-APs) may perform uplink communication.

The CS request field 1230 indicates whether a wireless medium status, NAV, or the like must be considered in the case where a receiving apparatus that receives a corresponding trigger frame transmits a corresponding uplink PPDU.

Ext>ext>ext> theext>ext>ext> HEext>ext>ext> -ext>ext>ext> SIGext>ext>ext> -ext>ext>ext> aext>ext>ext> informationext>ext>ext> fieldext>ext>ext> 1240ext>ext>ext> mayext>ext>ext> includeext>ext>ext> informationext>ext>ext> forext>ext>ext> controllingext>ext>ext> theext>ext>ext> contentext>ext>ext> ofext>ext>ext> aext>ext>ext> SIGext>ext>ext> -ext>ext>ext> aext>ext>ext> fieldext>ext>ext> (ext>ext>ext> i.e.ext>ext>ext>,ext>ext>ext> theext>ext>ext> HEext>ext>ext> -ext>ext>ext> SIGext>ext>ext> -ext>ext>ext> aext>ext>ext> fieldext>ext>ext>)ext>ext>ext> ofext>ext>ext> theext>ext>ext> uplinkext>ext>ext> ppduext>ext>ext> inext>ext>ext> responseext>ext>ext> toext>ext>ext> aext>ext>ext> correspondingext>ext>ext> triggerext>ext>ext> frameext>ext>ext>.ext>ext>ext>

The CP and LTF type field 1250 may include information on a CP length and an LTF length of an uplink PPDU transmitted in response to a corresponding trigger frame. The trigger type field 1260 may indicate the purpose for which the corresponding trigger frame is used, e.g., a typical trigger, being a beamforming trigger, requesting a block ACK/NACK, etc.

It may be assumed that the trigger type field 1260 of the trigger frame in this specification indicates a basic type of trigger frame for a typical trigger. For example, a basic type of trigger frame may be referred to as a basic trigger frame.

Fig. 13 shows an example of subfields included in the per-user information field. The user information field 1300 of fig. 13 may be understood as any one of the per-user information fields 1160#1 to 1160# n mentioned above with reference to fig. 11. Subfields included in the user information field 1300 of fig. 13 may be partially omitted, and additional subfields may be added. In addition, the length of the individual subfields shown may vary.

The user identifier field 1310 of fig. 13 indicates an identifier of an STA (i.e., a receiving STA) corresponding to per-user information. An example of the identifier may be all or part of an Association Identifier (AID) value of the receiving STA.

Additionally, RU allocation field 1320 may be included. That is, when the receiving STA identified through the user identifier field 1310 transmits the TB PPDU in response to the trigger frame, the TB PPDU is transmitted through the RU indicated by the RU allocation field 1320. In this case, the RU indicated by the RU allocation field 1320 may be the RU shown in fig. 5, 6, and 7.

The subfields of fig. 13 may include an encoding type field 1330. The coding type field 1330 may indicate a coding type of the TB PPDU. For example, the encoding type field 1330 may be set to "1" when BCC encoding is applied to TB PPDU, and the encoding type field 1330 may be set to "0" when LDPC encoding is applied.

In addition, the subfield of fig. 13 may include the MCS field 1340. The MCS field 1340 may indicate an MCS scheme applied to the TB PPDU. For example, the coding type field 1330 may be set to "1" when BCC coding is applied to the TB PPDU, and the coding type field 1330 may be set to "0" when LDPC coding is applied.

Hereinafter, a UL OFDMA-based random access (UORA) scheme will be described.

Figure 14 describes the technical features of the UORA scheme.

A transmitting STA (e.g., AP) may allocate six RU resources through a trigger frame as shown in fig. 14. Specifically, the AP may allocate 1RU resource (AID 0, RU 1), 2RU resource (AID 0, RU 2), 3 RU resource (AID 0, RU 3), 4RU resource (AID 2045, RU 4), 5RU resource (AID 2045, RU 5), and 6RU resource (AID 3, RU 6). Information related to AID 0, AID 3, or AID 2045 may be included, for example, in user identifier field 1310 of fig. 13. Information related to the RUs 1-6 may be included in, for example, the RU allocation field 1320 of fig. 13. AID =0 may mean a UORA resource for associated STAs, AID =2045 may mean a UORA resource for non-associated STAs. Therefore, the 1 st to 3 rd RU resources of fig. 14 may be used as UORA resources for associated STAs, the 4 th and 5 th RU resources of fig. 14 may be used as UORA resources for non-associated STAs, and the 6 th RU resource of fig. 14 may be used as typical resources for UL MUs.

In the example of fig. 14, the OFDMA random access backoff (OBO) of STA1 is reduced to 0, and STA1 randomly selects the 2 nd RU resource (AID 0, RU 2). In addition, since the OBO counter of STA2/3 is greater than 0, no uplink resource is allocated to STA 2/3. In addition, with regard to STA4 in fig. 14, since AID of STA4 (e.g., AID = 3) is included in the trigger frame, resources of RU 6 are allocated without backoff.

Specifically, since STA1 of fig. 14 is an associated STA, the total number of eligible RA RUs for STA1 is 3 (RU 1, RU 2, and RU 3), so STA1 decrements the OBO counter by 3 so that the OBO counter becomes 0. In addition, since STA2 of fig. 14 is an associated STA, the total number of eligible RA RUs for STA2 is 3 (RU 1, RU 2, and RU 3), so STA2 decrements the OBO counter by 3, but the OBO counter is greater than 0. Since STA3 of fig. 14 is a non-associated STA, the total number of eligible RA RUs for STA3 is 2 (RU 4, RU 5), and thus STA3 decrements the OBO counter by 2, but the OBO counter is greater than 0.

Fig. 15 shows an example of channels used/supported/defined within the 2.4GHz band.

The 2.4GHz band may be referred to by other terms such as the first band. In addition, the 2.4GHz band may mean a frequency domain that uses/supports/defines channels having a center frequency close to 2.4GHz (e.g., channels having a center frequency within 2.4 to 2.5 GHz).

Multiple 20MHz channels may be included in the 2.4GHz band. 20MHz within 2.4GHz may have multiple channel indices (e.g., index 1 through index 14). For example, the center frequency of the 20MHz channel allocated with channel index 1 may be 2.412GHz, the center frequency of the 20MHz channel allocated with channel index 2 may be 2.417GHz, and the center frequency of the 20MHz channel allocated with channel index N may be (2.407 +0.005 x N) GHz. The channel index may be referred to by various terms such as channel number, etc. The specific values of the channel index and center frequency may vary.

Fig. 15 illustrates 4 channels in the 2.4GHz band. Each of the 1 st through 4 th frequency domains 1510 through 1540 illustrated herein may include one channel. For example, frequency domain 1 1510 may include channel 1 (20 MHz channel with index 1). In this case, the center frequency of channel 1 may be set to 2412MHz. The 2 nd frequency domain 1520 may include channel 6. In this case, the center frequency of the channel 6 may be set to 2437MHz. The 3 rd frequency domain 1530 may include channel 11. In this case, the center frequency of the channel 11 may be set to 2462MHz. Frequency domain 4 1540 may include channel 14. In this case, the center frequency of the channel 14 may be set to 2484MHz.

Fig. 16 shows an example of channels used/supported/defined in the 5GHz band.

The 5GHz band may be referred to by other terms such as the second band. The 5GHz band may mean a frequency domain using/supporting/defining channels having center frequencies greater than or equal to 5GHz and less than 6GHz (or less than 5.9 GHz). Alternatively, the 5GHz band may include a plurality of channels between 4.5GHz and 5.5 GHz. The specific values shown in fig. 16 may vary.

The plurality of channels within the 5GHz band include the Unlicensed National Information Infrastructure (UNII) -1, UNII-2, UNII-3, and ISM. INII-1 may be referred to as UNII Low. UNII-2 may include frequency domains called UNII Mid and UNII-2 Extended. UNII-3 may be referred to as UNII-Upper.

A plurality of channels may be configured within the 5GHz band, and the bandwidth of each channel may be differently set to, for example, 20MHz, 40MHz, 80MHz, 160MHz, and the like. For example, the 5170MHz to 5330MHz frequency domains/ranges within UNII-1 and UNII-2 may be divided into eight 20MHz channels. The 5170MHz to 5330MHz frequency domain/range may be divided into four channels by the 40MHz frequency domain. The 5170MHz to 5330MHz frequency domain/range may be divided into two channels by the 80MHz frequency domain. Alternatively, the 5170MHz to 5330MHz frequency domain/range may be divided into one channel by the 160MHz frequency domain.

Fig. 17 shows an example of channels used/supported/defined within the 6GHz band.

The 6GHz band may be referred to by other terms such as a third band, etc. The 6GHz band may mean a frequency domain that uses/supports/defines channels having a center frequency greater than or equal to 5.9 GHz. The specific values shown in fig. 17 may vary.

For example, the 20MHz channel of FIG. 17 may be defined starting at 5.940 GHz. Specifically, among the 20MHz channels of fig. 17, the leftmost channel may have an index of 1 (or a channel index, a channel number, etc.), and 5.945GHz may be assigned as a center frequency. That is, the center frequency of the channel of index N may be determined to be (5.940 + 0.005N) GHz.

Thus, the index (or channel number) of the 2MHz channel of fig. 17 may be 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. In addition, the index of the 40MHz channel of fig. 17 may be 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227 according to the (5.940 +0.005 + n) GHz rule described above.

Although 20, 40, 80, and 160MHz channels are shown in the example of fig. 17, a 240MHz channel or a 320MHz channel may be additionally added.

Hereinafter, PPDUs transmitted/received in the STA of the present specification will be described.

Fig. 18 shows an example of a PPDU used in the present specification.

The PPDU of fig. 18 may be referred to as various terms such as an EHT PPDU, a TX PPDU, an RX PPDU, a first-type or nth-type PPDU, and the like. For example, in the present specification, a PPDU or an EHT PPDU may be referred to as various terms such as a TX PPDU, an RX PPDU, a first-type or N-type PPDU, and the like. In addition, the EHT PPDU may be used in an EHT system and/or a new WLAN system enhanced from the EHT system.

The PPDU of fig. 18 may indicate all or a portion of the type of PPDU used in an EHT system. For example, the example of fig. 18 may be used for both Single User (SU) mode and multi-user (MU) mode. In other words, the PPDU of fig. 18 may be a PPDU for one receiving STA or a plurality of receiving STAs. When the PPDU of fig. 18 is used for a trigger-based (TB) mode, the EHT-SIG of fig. 18 may be omitted. In other words, an STA that has received a trigger frame for an uplink MU (UL-MU) may transmit a PPDU omitting an EHT-SIG in the example of fig. 18.

In fig. 18, L-STF to EHT-LTF may be referred to as preambles or physical preambles and may be generated/transmitted/received/obtained/decoded in a physical layer.

The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG and EHT-SIG fields of FIG. 18 may be determined to be 312.5kHz, and the subcarrier spacing of the EHT-STF, EHT-LTF and data fields may be determined to be 78.125kHz. That is, the tone indices (or subcarrier indices) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may be expressed in units of 312.5kHz, and the tone indices (or subcarrier indices) of the EHT-STF, EHT-LTF, and data fields may be expressed in units of 78.125kHz.

In the PPDU of FIG. 18, L-LTE and L-STF may be the same as those in the legacy field.

For example, the L-SIG field of fig. 18 may include 24 bits of bit information. For example, the 24-bit information may include a 4-bit rate field, 1-bit reserved bits, a 12-bit length field, 1-bit parity bits, and 6-bit tail bits. For example, the 12-bit length field may include information related to the length or duration of the PPDU. For example, the length field of 12 bits may be determined based on the type of PPDU. For example, when the PPDU is non-HT, VHT PPDU, or EHT PPDU, the value of the length field may be determined as a multiple of 3. For example, when the PPDU is a HE PPDU, the value of the length field may be determined to be "a multiple of 3" +1 or "a multiple of 3" +2. In other words, the value of the length field may be determined to be "a multiple of 3" for a non-HT, VHT PPDI, or EHT PPDU, and "a multiple of 3" +1 or "a multiple of 3" +2 "for a HE PPDU.

For example, the transmitting STA may apply BCC coding based on a 1/2 coding rate to the 24 bits of information of the L-SIG field. Thereafter, the transmitting STA can obtain 48 bits of BCC coded bits. BPSK modulation may be applied to the 48-bit coded bits, thereby generating 48 BPSK symbols. The transmitting STA may map the 48 BPSK symbols to positions other than the pilot subcarrier { subcarrier index-21, -7, +7, +21} and the DC subcarrier { subcarrier index 0 }. As a result, 48 BPSK symbols may be mapped to subcarrier indices-26 to-22, -20 to-8, -6 to-1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA may additionally map the signals of { -1, -1,1} to the subcarrier indices { -28, -27, +27, +28}. The above signal may be used for channel estimation in the frequency domain corresponding to-28, -27, +27, + 28.

The transmitting STA may generate RL-SIG generated in the same manner as L-SIG. BPSK modulation may be applied to RL-SIG. The receiving STA may know that the RX PPDU is an HE PPDU or an EHT PPDU based on the presence of the RL-SIG.

General SIG (U-SIG) can be inserted after RL-SIG in FIG. 18. The U-SIB may be referred to by various terms such as a first SIG field, a first SIG, a first type of SIG, a control signal field, a first (type) control signal, and so on.

The U-SIG may include N bits of information, and may include information for identifying a type of the EHT PPDU. For example, the U-SIG may be configured based on two symbols (e.g., two contiguous OFDM symbols). Each symbol (e.g., OFDM symbol) of the U-SIG may have a duration of 4 μ β. Each symbol of the U-SIG may be used to transmit 26 bits of information. For example, each symbol of the U-SIG may be transmitted/received based on 52 data tones and 4 pilot tones.

For example, a-bit information (e.g., 52 uncoded bits) may be transmitted via the U-SIG (or U-SIG field). The first symbol of the U-SIG may transmit the first X bits of information (e.g., 26 uncoded bits) of the a bits of information, and the second symbol of the U-SIB may transmit the remaining Y bits of information (e.g., 26 uncoded bits) of the a bits of information. For example, the transmitting STA may obtain 26 uncoded bits included in each U-SIG symbol. The transmitting STA may perform convolutional encoding (i.e., BCC encoding) based on the rate of R =1/2 to generate 52 coded bits, and may perform interleaving on the 52 coded bits. The transmitting STA may perform BPSK modulation on the interleaved 52 coded bits to generate 52 BPSK symbols for allocation to respective U-SIG symbols. One U-SIG symbol may be transmitted based on 65 tones (subcarriers) from subcarrier index-28 to subcarrier index +28, except for DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) except for pilot tones (i.e., tones-21, -7, + 21).

For example, the a-bit information (e.g., 52 uncoded bits) generated by the U-SIG may include a CRC field (e.g., a field having a length of 4 bits) and a tail field (e.g., a field having a length of 6 bits). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on the 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits of the second symbol except for the CRC/tail field, and may be generated based on a conventional CRC calculation algorithm. In addition, the tail field may be used to terminate the trellis of the convolutional decoder, and may be set to, for example, "000000".

The a-bit information (e.g., 52 uncoded bits) transmitted by the U-SIG (or U-SIG field) may be divided into version independent bits and version dependent bits. For example, the version-independent bits may have a fixed size or a variable size. For example, the version-independent bits may be allocated only to the first symbol of the U-SIG, or the version-independent bits may be allocated to both the first and second symbols of the U-SIG. For example, the version-independent bits and the version-dependent bits may be referred to by various terms such as a first control bit, a second control bit, and so on.

For example, the version independent bits of the U-SIG may include a PHY version identifier of 3 bits. For example, a 3-bit PHY version identifier may include information related to the PHY version of the TX/RX PPDU. For example, a first value of the PHY version identifier of 3 bits may indicate that the TX/RX PPDU is an EHT PPDU. In other words, when the transmitting STA transmits the EHT PPDU, the PHY version identifier of 3 bits may be set to a first value. In other words, based on the PHY version identifier having the first value, the receiving STA may determine that the RX PPDU is an EHT PPDU.

For example, the version independent bit U-SIG may include a 1-bit UL/DL flag field. A first value of the 1-bit UL/DL flag field relates to UL communication and a second value of the UL/DL flag field relates to DL communication.

For example, the version independent bits of the U-SIG may include information about the TXOP length and information about the BSS color ID.

For example, when the EHT PPDU is divided into various types (e.g., various types such as an EHT PPDU related to SU mode, an EHT PPDU related to MU mode, an EHT PPDU related to TB mode, an EHT PPDU related to extended range transmission, etc.), information related to the type of the EHT PPDU may be included in a version-related bit of the U-SIG.

For example, the U-SIG may include: 1) A bandwidth field including information related to a bandwidth; 2) A field including information on an MCS scheme applied to the EHT-SIG; 3) An indication field including information on whether a dual subcarrier modulation (DCM) scheme is applied to the EHT-SIG; 4) A field including information on a number of symbols for the EHT-SIG; 5) A field including information on whether to generate the EHT-SIG across a full band; 6) A field including information on a type of the EHT-LTF/STF; and 7) information on fields indicating the length of the EHT-LTF and the length of the CP.

Preamble puncturing may be applied to the PPDU of fig. 18. Preamble puncturing means that puncturing is applied to a portion of the full frequency band (e.g., secondary 20MHz band). For example, when transmitting an 80MHz PPDU, an STA may apply puncturing to a secondary 20MHz band in the 80MHz band and may transmit the PPDU only through a primary 20MHz band and a secondary 40MHz band.

For example, the pattern of preamble puncturing may be preconfigured. For example, when the first puncturing pattern is applied, puncturing may be applied only to the secondary 20MHz band within the 80MHz band. For example, when the second puncturing pattern is applied, puncturing may be applied only to any one of two secondary 20MHz frequency bands included in the secondary 40MHz frequency band within the 80MHz frequency band. For example, when the third puncturing pattern is applied, puncturing may be applied only to the secondary 20MHz band included in the primary 80MHz band within the 160MHz band (or 80+80MHz band). For example, when the fourth puncturing is applied, puncturing may be applied to at least one 20MHz channel that does not belong to the primary 40MHz band in the presence of the primary 40MHz band included in the 80MHz band within the 160MHz band (or the 80+80MHz band).

Information related to preamble puncturing applied to the PPDU may be included in the U-SIG and/or the EHT-SIG. For example, the first field of the U-SIG may include information related to contiguous bandwidth, and the second field of the U-SIG may include information related to preamble puncturing applied to the PPDU.

For example, the U-SIG and the EHT-SIG may include information related to preamble puncturing based on the following method. When the bandwidth of the PPDU exceeds 80MHz, the U-SIG may be individually configured in units of 80 MHz. For example, when the bandwidth of the PPDU is 160MHz, the PPDU may include a first U-SIG for a first 80MHz frequency band and a second U-SIG for a second 80MHz frequency band. In this case, the first field of the first U-SIG may include information related to a 160MHz bandwidth, and the second field of the first U-SIG may include information related to preamble puncturing applied to the first 80MHz frequency band (i.e., information related to a preamble puncturing pattern). In addition, the first field of the second U-SIG may include information related to a 160MHz bandwidth, and the second field of the second U-SIG may include information related to preamble puncturing applied to the second 80MHz frequency band (i.e., information related to a preamble puncturing pattern). Further, the EHT-SIG adjacent to the first U-SIG may include information on preamble puncturing applied to the second 80MHz frequency band (i.e., information on a preamble puncturing pattern), and the EHT-SIG adjacent to the second U-SIG may include information on preamble puncturing applied to the first 80MHz frequency band (i.e., information on a preamble puncturing pattern).

Additionally or alternatively, the U-SIG and the EHT-SIG may include information related to preamble puncturing based on the following method. The U-SIG may include information related to preamble puncturing for all frequency bands (i.e., information related to a preamble puncturing pattern). That is, the EHT-SIG may not include information related to preamble puncturing, and only the U-SIG may include information related to preamble puncturing (i.e., information related to a preamble puncturing pattern).

The U-SIG may be configured in units of 20 MHz. For example, when an 80MHz PPDU is configured, the U-SIG may be duplicated. That is, four identical U-SIG may be included in an 80MHz PPDU. PPDUs exceeding 80MHz bandwidth may include different U-SIG.

The EHT-SIG of fig. 18 may include control information for the receiving STA. The EHT-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information about the number of symbols used for the EHT-SIG may be included in the U-SIG.

The EHT-SIG may include the technical features of HE-SIG-B described with reference to fig. 8 and 9. For example, as in the example of fig. 8, the EHT-SIG may include a common field and a user-specific field. Common fields of the EHT-SIG may be omitted and the number of user-specific fields may be determined based on the number of users.

As in the example of fig. 8, the common field of the EHT-SIG and the user-specific field of the EHT-SIG may be encoded separately. One user block field included in the user-specific field may include information for two users, but the most preferable one user block field included in the user-specific field may include information for one user. That is, one user block field of the EHT-SIG may include at most two user fields. As in the example of fig. 9, the various user fields may relate to MU-MIMO allocations or may relate to non-MU-MIMO allocations.

As in the example of fig. 8, the common field of the EHT-SIG may include CRC bits and tail bits. The length of the CRC bits may be determined to be 4 bits. The length of the tail bits may be determined to be 6 bits and may be set to "000000".

As in the example of fig. 8, the common field of the EHT-SIG may include RU allocation information. The RU allocation information may imply information on a location of an RU allocated with a plurality of users (i.e., a plurality of receiver STAs). As in table 1, the RU allocation information may be configured in units of 8 bits (or N bits).

The examples of tables 5 to 7 are examples of 8-bit (or N-bit) information for various RU allocations. The indices shown in the various tables may be modified and some of the entries in tables 5-7 may be omitted and entries (not shown) may be added.

The examples of tables 5 to 7 relate to information on the location of an RU allocated to a 20MHz band. For example, "index 0" of table 5 may be used in the case where nine 26-RUs are individually allocated (e.g., in the case where nine 26-RUs shown in fig. 5 are individually allocated).

Further, one STA may be allocated with a plurality of RUs in the EHT system. For example, with respect to "index 60" of table 6, one user (i.e., a receiving STA) may be allocated one 26-RU to the leftmost side of the 20MHz band, one 26-RU and one 52-RU may be allocated to the right side thereof, and five 26-RUs may be allocated to the right side thereof individually.

[ Table 5]

[ Table 6]

[ Table 7]

A mode may be supported in which the common fields of the EHT-SIG are omitted. A mode in which the common field of the EHT-SIG is omitted may be referred to as a compressed mode. When using compressed mode, multiple users (i.e., multiple receiving STAs) may decode a PPDU (e.g., a data field of the PPDU) based on non-OFDMA. That is, multiple users of the EHT PPDU may decode PPDUs (e.g., data fields of PPDUs) received over the same frequency band. Further, when using the non-compressed mode, multiple users of the EHT PPDU may decode the PPDU (e.g., a data field of the PPDU) based on OFDMA. That is, multiple users of the EHT PPDU may receive the PPDU (e.g., a data field of the PPDU) through different frequency bands.

The EHT-SIG may be configured based on various MCS schemes. As described above, information on the MCS scheme applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be configured based on a DCM scheme. For example, among N data tones (e.g., 52 data tones) allocated for the EHT-SIG, a first modulation scheme may be applied to half of the adjacent tones, and a second modulation scheme may be applied to the remaining half of the adjacent tones. That is, the transmitting STA may modulate specific control information through a first symbol and allocate it to half of the adjacent tones using a first modulation scheme, and may modulate the same control information through a second symbol and allocate it to the remaining half of the adjacent tones using a second modulation scheme. As described above, information (e.g., 1-bit field) regarding whether to apply the DCM scheme to the EHT-SIG may be included in the U-SIG.

The HE-STF of fig. 18 may be used to improve automatic gain control estimation in a Multiple Input Multiple Output (MIMO) environment or an OFDMA environment. The HE-LTF of fig. 18 may be used to estimate a channel in a MIMO environment or an OFDMA environment.

The EHT-STF of fig. 18 may be set to various types. For example, a first type of STF (e.g., 1x STF) may be generated based on a first type STF sequence in which non-zero coefficients are arranged at intervals of 16 subcarriers. The STF signal generated based on the first type STF sequence may have a period of 0.8 μ s, and the periodic signal of 0.8 μ s may be repeated 5 times to become the first type STF having a length of 4 μ s. For example, the second type of STF (e.g., 2x STF) may be generated based on a second type STF sequence in which non-zero coefficients are arranged at intervals of 8 subcarriers. The STF signal generated based on the second-type STF sequence may have a period of 1.6 μ s, and the periodic signal of 1.6 μ s may be repeated 5 times to become the second-type STF having a length of 8 μ s. Hereinafter, an example of a sequence for configuring the EHT-STF (i.e., an EHT-STF sequence) is presented. The following sequence may be modified in various ways.

The EHT-STF may be configured based on the following sequence M.

< formula 1>

M＝{-1,-1,-1,1,1,1,-1,1,1,1,-1,1,1,-1,1}

The EHT-STF for the 20MHz PPDU may be configured based on the following equation. The following example may be a first type (i.e., 1x STF) sequence. For example, the first type sequence may not be included in a Trigger (TB) -based PPDU but included in an EHT-PPDU. In the following equation, (a: b: c) may mean a duration of a b tone interval (i.e., subcarrier interval) defined from a tone index (i.e., subcarrier index) "a" to a tone index "c". For example, the following equation 2 may represent a sequence defined as a 16-tone interval from tone index-112 to tone index 112. Since a subcarrier spacing of 78.125kHz is applied to the EHT-STR, a 16-tone interval may mean that EHT-STF coefficients (or elements) are arranged at intervals of 78.125 × 16=1250 kHz. In addition, one means multiplication, and sqrt () means square root. In addition, j means an imaginary number.

< formula 2>

EHT-STF(-112:16:112)＝{M}*(1+j)/sqrt(2)

EHT-STF(0)＝0

The EHT-STF for the 40MHz PPDU may be configured based on the following equation. The following example may be a first type (i.e., 1x STF) sequence.

< formula 3>

EHT-STF(-240:16:240)＝{M,0,-M}*(1+j)/sqrt(2)

The EHT-STF for the 80MHz PPDU may be configured based on the following equation. The following example may be a first type (i.e., 1x STF) sequence.

< formula 4>

EHT-STF(-496:16:496)＝{M,1,-M,0,-M,1,-M}*(1+j)/sqrt(2)

The EHT-STF for the 160MHz PPDU may be configured based on the following equation. The following example may be a first type (i.e., 1x STF) sequence.

< formula 5>

EHT-STF(-1008:16:1008)＝{M,1,-M,0,-M,1,-M,0,-M,-1,M,0,-M,1,-M}*(1+j)/sqrt(2)

In EHT-STF for 80+80MHz PPDU, the sequence for the lower 80MHz may be the same as equation 4. In EHT-STF for 80+80MHz PPDU, the sequence for the upper 80MHz may be configured based on the following equation.

< equation 6>

EHT-STF(-496:16:496)＝{-M,-1,M,0,-M,1,-M}*(1+j)/sqrt(2)

The following equations 7 to 11 relate to examples of the second type (i.e., 2x STF) sequence.

< formula 7>

EHT-STF(-120:8:120)＝{M,0,-M}*(1+j)/sqrt(2)

The EHT-STF for the 40MHz PPDU may be configured based on the following equation.

< equation 8>

EHT-STF(-248:8:248)＝{M,-1,-M,0,M,-1,M}*(1+j)/sqrt(2)

EHT-STF(-248)＝0

EHT-STF(248)＝0

The EHT-STF for the 80MHz PPDU may be configured based on the following equation.

< formula 9>

EHT-STF(-504:8:504)＝{M,-1,M,-1,-M,-1,M,0,-M,1,M,1,-M,1,-M}*(1+j)/sqrt(2)

The EHT-STF for the 160MHz PPDU may be configured based on the following equation.

< formula 10>

EHT-STF(-1016:16:1016)＝{M,-1,M,-1,-M,-1,M,0,-M,1,M,1,-M,1,-M,0,-M,1,-M,1,M,1,-M,0,-M,1,M,1,-M,1,-M}*(1+j)/sqrt(2)

EHT-STF(-8)＝0，EHT-STF(8)＝0,

EHT-STF(-1016)＝0，EHT-STF(1016)＝0

In EHT-STF for 80+80MHz PPDU, the sequence for the lower 80MHz may be the same as formula 9. In EHT-STF for 80+80MHz PPDU, the sequence for the upper 80MHz may be configured based on the following equation.

< formula 11>

EHT-STF(-504:8:504)＝{-M,1,-M,1,M,1,-M,0,-M,1,M,1,-M,1,-M}*(1+j)/sqrt(2)

EHT-STF(-504)＝0,

EHT-STF(504)＝0

The EHT-LTFs may have a first type, a second type, and a third type (i.e., 1x, 2x, 4x LTFs). For example, the first/second/third type LTFs may be generated based on LTF sequences in which non-zero coefficients are arranged at intervals of 4/2/1 of subcarriers. The first/second/third type LTFs may have a time length of 3.2/6.4/12.8. Mu.s. In addition, GI having various lengths (e.g., 0.8/1/6/3.2 μ s) may be applied to the first/second/third type LTFs.

Ext> informationext> onext> theext> typeext> ofext> STFext> andext> /ext> orext> LTFext> (ext> includingext> alsoext> informationext> onext> GIext> appliedext> toext> LTFext>)ext> mayext> beext> includedext> inext> theext> SIGext> -ext> aext> fieldext> andext> /ext> orext> SIGext> -ext> bext> fieldext> ofext> fig.ext> 18ext>,ext> andext> theext> likeext>.ext>

The PPDU (e.g., EHT-PPDU) of fig. 18 may be configured based on the examples of fig. 5 and 6.

For example, an EHT PPDU transmitted over a 20MHz band (i.e., a 20MHz EHT PPDU) may be configured based on the RU of fig. 5. That is, the positions of the RUs of the EHT-STF, the EHT-LTF, and the data field included in the EHT PPDU may be determined as shown in FIG. 5.

The EHT PPDU transmitted over the 40MHz band (i.e., the 40MHz EHT PPDU) may be configured based on the RU of fig. 6. That is, the location of the RU of the EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in FIG. 6.

Since the RU position of fig. 6 corresponds to 40MHz, a tone plan for 80MHz can be determined when the pattern of fig. 6 is repeated twice. That is, the 80MHz EHT PPDU may be transmitted based on a new tone plan in which the RU of fig. 6 is repeated twice instead of the RU of fig. 7.

When the pattern of fig. 6 is repeated twice, 23 tones (i.e., 11 guard tones +12 guard tones) may be configured in the DC region. That is, a tone plan for an 80MHz EHT PPDU based on an OFDMA allocation may have 23 DC tones. In contrast, an 80MHz EHT PPDU based on a non-OFDMA allocation (i.e., a non-OFDMA full bandwidth 80MHz PPDU) may be configured based on 996-RU and may include 5 DC tones, 12 left guard tones, and 11 right guard tones.

The tone plan for 160/240/320MHz may be configured in such a way that the pattern of fig. 6 is repeated a number of times.

The PPDU of fig. 18 may be determined (or identified) as an EHT PPDU based on the following method.

The receiving STA may determine the type of RX PPDU as an EHT PPDU based on the following aspects. For example, 1) when a first symbol following an L-LTF signal of an RX PPDU is a BPSK symbol; 2) When RL-SIG of which L-SIG of RX PPDU is repeated is detected; and 3) when a result of applying "modulo 3" to a value of a length field of L-SIG of the RX PPDU is detected as "0", the RX PPDU may be determined as the EHT PPDU. When the RX PPDU is determined to be an EHT PPDU, the receiving STA may detect a type of the EHT PPDU (e.g., SU/MU/trigger-based/extended range type) based on bit information included in a symbol following the RL-SIG of fig. 18. In other words, based on: 1) A first symbol following the L-LTF signal as a BPSK symbol; 2) An RL-SIG field contiguous with and identical to the L-SIG field; 3) An L-SIG including a length field with the result of applying modulo 3 set to 0; and 4) the 3-bit PHY version identifier (e.g., PHY version identifier having a first value) of the above U-SIG, the receiving STA may determine the RX PPDU as an EHT PPDU.

For example, the receiving STA may determine the type of RX PPDU as an EHT PPDU based on the following aspects. For example, 1) when the first symbol following the L-LTF signal is a BPSK symbol; 2) When RL-SIG in which L-SIG is repeated is detected; and 3) when a result of applying modulo 3 to the value of the length field of the L-SIG is detected as '1' or '2', the RX PPDU may be determined to be an HE PPDU.

For example, the receiving STA may determine the type of RX PPDU as a non-HT, and VHT PPDU based on the following aspects. For example, 1) when the first symbol following the L-LTF signal is a BPSK symbol; and 2) when RL-SIG in which L-SIG is repeated is not detected, the RX PPDU may be determined to be non-HT, and VHT PPDUs. In addition, even if the receiving STA detects RL-SIG repetition, when a result of applying modulo 3 to a length value of L-SIG is detected as "0", the RX PPDU may be determined to be non-HT, and VHT PPDUs.

In the following examples, signals represented as (TX/RX/UL/DL) signals, (TX/RX/UL/DL) frames, (TX/RX/UL/DL) packets, (TX/RX/UL/DL) data units, (TX/RX/UL/DL) data, etc. may be signals transmitted/received based on the PPDU of fig. 18. The PPDU of fig. 18 may be used to transmit/receive various types of frames. For example, the PPDU of fig. 18 may be used for the control frame. Examples of the control frame may include a Request To Send (RTS), clear To Send (CTS), power save poll (PS-poll), blockackkreq, blockAck, null Data Packet (NDP) announcement, and trigger frame. For example, the PPDU of fig. 18 may be used for the management frame. Examples of management frames may include beacon frames, (re) association request frames, (re) association response frames, probe request frames, and probe response frames. For example, the PPDU of fig. 18 may be used for a data frame. For example, the PPDU of fig. 18 may be used to simultaneously transmit at least two or more of a control frame, a management frame, and a data frame.

Fig. 19 shows an example of a transmitting apparatus and/or a receiving apparatus of a modification of the present specification.

Each device/STA of subgraph (a)/(b) of fig. 1 can be modified as shown in fig. 19. The transceiver 630 of fig. 19 may be the same as the transceivers 113 and 123 of fig. 1. The transceiver 630 of fig. 19 may include a receiver and a transmitter.

The processor 610 of fig. 19 may be the same as the processors 111 and 121 of fig. 1. Alternatively, the processor 610 of FIG. 19 may be the same as the processing chips 114 and 124 of FIG. 1.

Memory 620 of fig. 19 may be the same as memory 112 and 122 of fig. 1. Alternatively, the memory 620 of fig. 19 may be a separate external memory different from the memories 112 and 122 of fig. 1.

Referring to fig. 19, a power management module 611 manages power for processor 610 and/or transceiver 630. The battery 612 supplies power to the power management module 611. The display 613 outputs the result processed by the processor 610. The keypad 614 receives input to be used by the processor 610. The keypad 614 may be displayed on the display 613. The SIM card 615 may be an integrated circuit used to securely store an International Mobile Subscriber Identity (IMSI) and its associated key, which is used to identify and authenticate users on mobile telephone devices, such as mobile telephones and computers.

Referring to fig. 19, the speaker 640 may output a result related to the sound processed by the processor 610. The microphone 641 may receive input related to a sound to be used by the processor 610.

Hereinafter, technical features of channel bonding supported by the STA of the present disclosure will be described.

For example, in an IEEE802.11 n system, 40MHz channel bonding may be performed by combining two 20MHz channels. In addition, 40/80/160MHz channel bonding may be performed in IEEE802.11 ac systems.

For example, the STA may perform channel bonding for a primary 20MHz channel (P20 channel) and a secondary 20MHz channel (S20 channel). A backoff count/counter may be used in the channel bonding process. The backoff count value may be selected as a random value and decremented during the backoff interval. In general, when the backoff count value becomes 0, the STA may attempt to access the channel.

During the backoff interval, when the P20 channel is determined to be in an idle state and the backoff count value of the P20 channel becomes 0, the STA performing channel bonding determines whether the S20 channel maintains the idle state for a certain period of time (e.g., a point coordination function interframe space (PIFS)). If the S20 channel is in an idle state, the STA may perform bonding on the P20 channel and the S20 channel. That is, the STA may transmit a signal (PPDU) through a 40MHz channel (i.e., a 40MHz bonded channel) including a P20 channel and an S20 channel.

Fig. 20 shows an example of channel bonding. As shown in fig. 20, the primary 20MHz channel and the secondary 20MHz channel can be grouped into 40MHz channels (primary 40MHz channels) by channel bonding. That is, the bonded 40MHz channels may include a primary 20MHz channel and a secondary 20MHz channel.

Channel bonding may be performed when a channel adjacent to the primary channel is in an idle state. That is, the primary 20MHz channel, the secondary 40MHz channel, and the secondary 80MHz channel may be bonded in sequence. However, if the secondary 20MHz channel is determined to be in a busy state, channel bonding cannot be performed even if all other secondary channels are in an idle state. In addition, when it is determined that the secondary 20MHz channel is in the idle state and the secondary 40MHz channel is in the busy state, channel bonding may be performed only on the primary 20MHz channel and the secondary 20MHz channel.

Hereinafter, preamble puncturing supported by the STA in the present disclosure will be described.

For example, in the example of fig. 20, if the primary 20MHz channel, the secondary 40MHz channel, and the secondary 80MHz channel are all in an idle state, but the secondary 20MHz channel is in a busy state, it may not be possible to bind to the secondary 40MHz channel and the secondary 80MHz channel. Ext> inext> thisext> caseext>,ext> theext> STAext> mayext> configureext> theext> 160ext> MHzext> PPDUext> andext> mayext> performext> preambleext> puncturingext> onext> aext> preambleext> (ext> e.g.ext>,ext> Lext> -ext> STFext>,ext> Lext> -ext> LTFext>,ext> Lext> -ext> SIGext>,ext> RLext> -ext> SIGext>,ext> Uext> -ext> SIGext>,ext> HEext> -ext> SIGext> -ext> aext>,ext> HEext> -ext> SIGext> -ext> bext>,ext> HEext> -ext> STFext>,ext> HEext> -ext> LTFext>,ext> ehtext> -ext> SIGext>,ext> ehtext> -ext> STFext>,ext> ehtext> -ext> LTFext>,ext> etc.ext>)ext> transmittedext> throughext> theext> secondaryext> 20ext> MHzext> channelext>,ext> soext> thatext> theext> STAext> mayext> transmitext> aext> signalext> throughext> aext> channelext> inext> anext> idleext> stateext>.ext> In other words, the STA may perform preamble puncturing for some frequency bands of the PPDU. Ext> informationext> regardingext> preambleext> puncturingext> (ext> e.g.ext>,ext> informationext> regardingext> 20ext> /ext> 40ext> /ext> 80ext> MHzext> channelsext> /ext> bandsext> toext> whichext> puncturingext> isext> appliedext>)ext> mayext> beext> includedext> inext> aext> signalext> fieldext> (ext> e.g.ext>,ext> HEext> -ext> SIGext> -ext> aext>,ext> uext> -ext> SIGext>,ext> ehtext> -ext> SIGext>)ext> ofext> theext> PPDUext>.ext>

Hereinafter, technical features of a multi-link (ML) supported by the STA of the present disclosure will be described.

The STAs (AP and/or non-AP STAs) of the present disclosure may support multi-link (ML) communications. ML communication may refer to communication supporting multiple links. Links associated with ML communication may include channels in the 2.4GHz band shown in FIG. 15, the 5GHz band shown in FIG. 16, and the 6GHz band shown in FIG. 17 (e.g., 20/40/80/160/240/320MHz channels).

The plurality of links for ML communication may be set in various ways. For example, the multiple links that one STA supports for ML communication may be multiple channels in the 2.4GHz band, multiple channels in the 5GHz band, and multiple channels in the 6GHz band. Alternatively, the plurality of links for ML communication supported by one STA may be a combination of at least one channel in the 2.4GHz band (or 5GHz/6GHz band) and at least one channel in the 5GHz band (or 2.4GHz/6GHz band). Further, at least one of the links for ML communication supported by one STA may be a channel to which preamble puncturing is applied.

The STA may perform ML setup to perform ML communication. The ML setting may be performed based on a management frame or a control frame such as a beacon, a probe request/response, an association request/response, and the like. For example, information about ML settings may be included in element fields included in beacons, probe requests/responses, association requests/responses, and the like.

When the ML setup is complete, an enabled link for ML communication may be determined. The STA may perform frame exchange through at least one of the plurality of links determined to be link-enabled. For example, the enable link may be used for at least one of management frames, control frames, and data frames.

When one STA supports multiple links, the transceiver supporting each link may operate as one logical STA. For example, one STA supporting two links may be denoted as one multi-link device (MLD), including a first STA for a first link and a second STA for a second link. For example, one AP supporting two links may be denoted as one AP MLD, including a first AP for a first link and a second AP for a second link. In addition, one non-AP supporting two links may be denoted as one non-AP MLD, including a first STA for the first link and a second STA for the second link.

Hereinafter, more specific features related to the ML setting are described.

The MLD (AP MLD and/or non-AP MLD) may transmit information about a link that the corresponding MLD can support through the ML setting. The link information may be configured in various ways. For example, the information on the link may include at least one of 1) information on whether the MLD (or STA) supports simultaneous RX/TX operation, 2) information on the number/upper limit of uplinks/downlinks supported by the MLD (or STA), 3) information on the location/band/resource of the uplinks/downlinks supported by the MLD (or STA), 4) information on the frame type (management, control, data, etc.) available or preferred in at least one uplink/downlink, 5) information on the ACK policy available or preferred in at least one uplink/downlink, and 6) information on the Traffic Identifier (TID) available or preferred in at least one uplink/downlink. The TID is related to priority of traffic data and is expressed as eight types of values according to the conventional wireless LAN standard. That is, eight TID values corresponding to four Access Categories (AC) (AC _ Background (AC _ BK), AC _ Best efficiency (AC _ BE), AC _ Video (AC _ VI), AC _ Voice (AC _ VO)) according to the conventional WLAN standard may BE defined.

For example, it may be preset that all TIDs are mapped for uplink/downlink. In particular, if no negotiation is made with ML settings, if all TIDs are used for ML communication, and if a mapping between uplink/downlink and TID is negotiated with additional ML settings, the negotiated TIDs may be used for ML communication.

With the ML setting, a plurality of links available through the transmitting MLD and the receiving MLD can be set in relation to ML communication, and this can be referred to as "enabled links". An "enabled link" may be referred to differently by various expressions. For example, it may be referred to as various expressions such as a first link, a second link, a transmission link, and a reception link.

After the ML setting is completed, the MLD may update the ML setting. For example, when it is necessary to update information about a link, the MLD may send information about the new link. The information on the new link may be transmitted based on at least one of a management frame, a control frame, and a data frame.

In the very high throughput (EHT) standard discussed after ieee802.11ax, the introduction of HARQ is being considered. When HARQ is introduced, coverage may be extended in a low signal-to-noise ratio (SNR) environment, i.e., an environment in which the distance between a transmitting terminal and a receiving terminal is long, and higher throughput may be obtained in a high SNR environment.

The apparatus described below may be the devices of fig. 1 and/or fig. 19, and the PPDU may be the PPDU of fig. 18. The apparatus may be an AP or a non-AP STA. The devices described below may be multi-link capable AP multi-link devices (MLD) or non-AP STA MLD.

In the very high throughput (EHT) standard discussed after 802.11ax, a multilink environment using one or more frequency bands simultaneously is being considered. When the device supports multiple links or multiple links, the device may use one or more frequency bands (e.g., 2.4GHz, 5GHz, 6GHz, 60GHz, etc.) simultaneously or alternately.

Hereinafter, although described in the form of a multilink, the frequency band may be configured in various other forms. In this specification, terms such as multilink, etc. may be used, however, for the convenience of the following description, some embodiments may be described based on multilink.

In the following description, MLD refers to a multi-link device. MLD has one or more connected STAs and one MAC Service Access Point (SAP) connected to the upper link layer (logical link control LLC). MLD may mean a physical device or a logical device. Hereinafter, the device may mean an MLD.

In the following description, a transmitting device and a receiving device may be referred to as MLD. The first link of the reception/transmission apparatus may be a terminal (e.g., STA or AP) that performs signal transmission/reception through the first link included in the reception/transmission apparatus. The second link of the reception/transmission apparatus may be a terminal (e.g., STA or AP) that performs signal transmission/reception through the second link included in the reception/transmission apparatus.

Ieee802.11be can support two types of multilink operation. For example, simultaneous Transmit and Receive (STR) and non-STR operations may be considered. For example, STR may be referred to as asynchronous multilink operation and non-STR may be referred to as synchronous multilink operation. The multilink may include multiple frequency bands. That is, a multi-link may mean a link included in a plurality of frequency bands, or may mean a plurality of links included in one frequency band.

The EHT (11 be) may consider a multilink technology, in which multilinks may include multiple frequency bands. That is, the multilink may represent links of a plurality of frequency bands, and may represent a plurality of multilinks within one frequency band. Two types of multilink operation are being considered. Consider asynchronous operation that allows simultaneous TX/RX on multiple links and synchronous operation that is not possible with simultaneous TX/RX on multiple links. Hereinafter, the capability of allowing simultaneous reception and transmission in multiple links is referred to as STR (simultaneous transmission and reception), the STA having STR capability is referred to as STR MLD (multi-link device), and the STA not having STR capability is referred to as non-STR MLD.

In the very high throughput (EHT) standard discussed after 802.11ax, a multi-band environment using one or more frequency bands simultaneously is considered. When the AP or the STA supports multiple frequency bands or multiple links, the AP and the STA may use one or more frequency bands (e.g., 2.4GHz, 5GHz, 6GHz, 60GHz, etc.) simultaneously or alternately. For example, multiband/link transmission can be classified into two types as shown in fig. 21.

Fig. 21 shows an embodiment of a multilink transmission method.

Referring to fig. 21, in case of STR transmission (e.g., asynchronous transmission), transmission and reception can be freely performed in each link. In the case of non-STR transmission (e.g., synchronous transmission), when transmission is performed in some links, only transmission may be performed in other links, and reception may not be performed.

In the existing single band/link case, ack frames are transmitted using the link over which the data is transmitted. Accordingly, when transmission is performed using two or more frequency bands or links, it can be estimated that Ack frames of data of the respective links operate in a link-specific manner (i.e., ack is transmitted to the corresponding link transmitting the data). However, in this case, there is a possibility that the Ack frame is lost due to a power imbalance problem or a collision problem between the AP and the STA. Specifically, the link quality of a particular link may not be as reliable as the link quality of other links due to frequency characteristics or OBSS density levels, etc. According to embodiments of the present description, time resources may be more efficiently used through a reliable Ack procedure using a multi-link environment.

Further, the Simultaneous Transmission and Reception (STR) capability may vary according to the capability of the terminal or the frequency characteristics occupied by a plurality of links. In particular, if the center frequencies of a plurality of links are close, or if one link is used for transmission and the other link is used for reception due to a design problem within each terminal, interference may occur even if the two links have different frequencies/frequency bands. Therefore, even if the AP has STR capability, a channel access method should be designed in consideration of the case where the STA does not support STR.

In addition, in the course of improving the 802.11WLAN standard, the data rate also increases, but the length of PPDU also increases significantly. In particular, when a large-sized PPDU is transmitted in a congested environment where a large number of STAs exist, if RTS/CTS is not used, collision is likely to occur and overall network throughput may be significantly reduced. Therefore, RTS/CTS may need to be used.

Fig. 22 illustrates an embodiment of inter-link interference.

Referring to fig. 22, collision may occur in performing channel access and data transmission/reception using RTS/CTS in each of two links (i.e., link a, link B). In the case where one link (e.g., link B) is not idle, and thus the AP MLD starts transmitting on the other link (e.g., link a), if the channel of the other link becomes idle, and thus the AP MLD transmits a (MU-) RTS, the non-AP MLD applies a CTS response, which may result in inter-link interference in the receiving link. That is, when the non-AP MLD that does not support STR transmits a CTS frame on link B and receives DATA1 on link a, collision between the two links may occur.

A method of solving the inter-link interference problem occurring in the non-STR STA as described above is described in the specification described below.

Although an RTS frame is presented as an example of channel occupation in the description described below, the RTS frame may be configured in various other forms. That is, although an RTS frame, an MU-RTS frame, or the like may be used in this specification, hereinafter for convenience of description, some examples will be described based on the RTS frame.

Although the frequency band is described in the form of a multilink in the specification described below, the frequency band may be configured in various forms. That is, although multiband, multilink, etc. may be used in this specification, hereinafter, for convenience of description, some examples are described based on multilink.

Although the number of links in the multilink environment is indicated as two in the description described below, it is equally applicable to the case where the number of links is greater than 2. Hereinafter, for convenience of description, some examples are described based on a multilink environment in which the number of links is 2.

Although the description described below indicates that channel access is initiated first in link a, this may also apply to the case where channel access is initiated first in link B. For convenience of description, hereinafter, in some examples, a link that first initiates channel access will be referred to as link a, and the other links will be referred to as link B.

In the following description, MLD refers to a multi-link device. MLD has one or more associated STAs and has one MAC Service Access Point (SAP) connected to the upper link layer (logical link control (LLC)). MLD may refer to a physical device or a logical device. In the description described below, a specific MLD is defined as a non-STR when transmission and reception cannot be simultaneously performed from two or more links at the same time, and otherwise, as an STR when transmission and reception can be simultaneously performed from two or more links. That is, when some STAs of the MLD perform transmission/reception, the MLD may be STR if other STAs of the MLD can perform reception/transmission, and when some STAs of the MLD perform transmission/reception, the MLD may be non-STR if other STAs of the MLD cannot perform reception/transmission. STR and non-STR capabilities may change dynamically, and STR capabilities may vary depending on which link set is selected.

Although it is assumed in the description described below that the AP MLD is STR and the non-AP MLD is non-STR, this may be equally applied to the opposite case, i.e., the case where the AP MLD is non-STR and the non-AP MLD is STR. Furthermore, this may also be applied to the case where both the AP MLD and the non-AP MLD are non-STR.

DL-DLMU cases

Fig. 23 illustrates an embodiment of internal interference occurring in a non-STR linkset.

Referring to fig. 23, the AP MLD may transmit data to the non-AP MLD. Since the channel of link B is busy, the AP LD may perform channel access only on link a. When it is determined that the channel of link B is idle while data transmission is performed on link a, the AP MLD may attempt channel access on link B.

In the existing RTS/CTS procedure, if subsequent data can be received, the STA receiving the RTS should respond with a CTS frame. However, if the non-AP MLD, which is a non-STR, transmits a CTS frame, since this causes inter-link interference to the link a, collision may occur with the DATA1 that has been being received.

Fig. 24 illustrates an embodiment of an RTS/CTS transmission method.

One approach that can solve the problem that occurs in fig. 23 is shown in fig. 24. Referring to fig. 24, while the AP MLD a transmits PPDUs to the STAs MLD B and MLD C on the link a, the channel of the link B may become idle, and thus the AP MLD a may transmit MU-RTS to transmit PPDUs to the MLD B, MLD C and MLD after channel access. MLD B may not respond with a CTS (intentionally) even if an RTS is received, since the CTS response may cause interference to the reception of link a. That is, while MLD B may send CTS upon receiving RTS on link B, it may not send CTS on this basis since DATA1 is being received on link a. For example, since MLD B is the recipient of PPDU transmitted by AP MLD a that has obtained a TXOP on link a (i.e., since MLD B is the TXOP responder), a CTS may not be transmitted even if an RTS is received on link B. That is, MLD B does not send a CTS even if it receives an RTS on link B, based on MLD B being a TXOP responder on link a. For example, since link a and link B of the non-AP MLD B are a non-STR link pair, and an STA operating on link a as one of the STR link pair is a TXOP responder, an STA operating on link B as the other link of the non-STR link pair does not send a CTS even if it receives an RTS. While no CTS is sent, MLD B may receive DATA2 on link B. MLD B may send an ACK when DATA2 is received.

Since the MLD C is an MLD supporting STR, the MLD C can respond with CTS. MLD is a set of links that do not support STR, but may use a CTS response since reception is not being performed on other links and therefore does not cause interference in CTS response transmission.

Fig. 25 illustrates an embodiment of an RTS/CTS transmission method.

Another method that can solve the problem occurring in fig. 23 is shown in fig. 25. Referring to fig. 25, while the AP MLD a transmits PPDUs to the STAs MLD B and MLD C on the link a, the channel of the link B may become idle, and thus the AP MLD a may transmit CTS-to-self (self CTS) to transmit PPDUs to the MLD B, MLD C and MLD after channel access. That is, the AP MLD A may send a CTS-to-self frame instead of an RTS frame. In order not to send CTS frames that may cause interference, the AP MLD may perform channel protection using CTS-to-self frames instead of RTS frames.

Fig. 26 illustrates an embodiment of an RTS/CTS transmission method.

One approach that can solve the problem that occurs in fig. 23 is shown in fig. 26. Referring to fig. 26, while the AP MLD a transmits PPDUs to the STAs MLD B and MLD C on the link a, the channel of the link B may become idle, and thus the AP MLD a may transmit MU-RTS to transmit PPDUs to the MLD B, MLD C and MLD after channel access. MLD B does not respond with a CTS in response to the MU-RTS sent by AP MLD a on link B, since the CTS response may cause interference to the reception of link a. MLD C may respond with CTS because it is an MLD that supports STR. MLD is a link set that does not support STR, but does not cause interference in CTS response transmission since reception is not being performed on other links, so a CTS response is available.

Hereinafter, an example of the MU-RTS frame format (i.e., a method of preventing the MLD B from responding with CTS in response to the MU-RTS transmitted by the AP MLD a on the link B) will be described. The trigger frame currently used in 802.11ax is shown in fig. 27. STAs to be subject to trigger frame reception may be identified by whether AID12 matches.

Fig. 27 to 29 show an embodiment of a trigger frame format.

Excluding the user information field: for example, referring to fig. 27, ap MLD a may know whether MLD B is non-STR MLD (through previous capability information exchange, etc.) and whether MLD B is performing reception on link a. Thus, as shown in FIG. 27, the user information field of the MU-RTS sent by AP MLD A on link B may not include the field corresponding to MLD B.

The additional indication is: for example, referring to fig. 28, ap MLD a may know whether MLD B is non-STR MLD and whether MLD B is performing reception on link a. A particular field (e.g., a reserved field) of a user information field of the MU-RTS transmitted by the AP MLD a on link B corresponding to MLD B (e.g., a user information field related to AID12 of MLD B) may include information related to whether or not to perform a CTS response (e.g., a CTS response indication).

Indication of use of RU allocation field: for example, referring to fig. 29, it may be considered that an MLD (e.g., MLD B) that does not send a CTS is not allocated an RU to be occupied by the next CTS. Accordingly, in an RU allocation field of a user information field of the MU-RTS transmitted by the AP MLD a on the link B corresponding to the MLD B (e.g., a user information field related to the AID12 of the MLD B), a value defined as reserved (e.g., a value other than a predefined value) may be included for indicating that an RU for CTS is not allocated (i.e., information indicating that a CTS is not transmitted).

Fig. 30 illustrates an embodiment of an operation of receiving an MLD.

Referring to fig. 30, a receiving MLD may include a first station and a second Station (STA). A first STA may operate on a first link and a second STA may operate on a second link.

The receiving MLD may receive a second RTS frame on the first link (S3010).

The receiving MLD may send a CTS frame to the second RTS frame on the first link (S3020).

The receiving MLD may receive a first Physical Protocol Data Unit (PPDU) including first data on the first link (S3030).

The receiving MLD may receive a first Request To Send (RTS) frame on the second link while receiving the first PPDU on the first link (S3040). Based on the first PPDU being received on the first link, the receiving MLD may skip a Clear To Send (CTS) frame transmission for the first RTS frame. For example, since the receiving MLD is a recipient of PPDU transmitted by the transmitting MLD that has obtained the TXOP on the first link (i.e., since the receiving MLD is a TXOP responder), a CTS is not transmitted even if an RTS is received on the second link. That is, the receiving MLD does not send a CTS even if an RTS is received on the second link, based on the receiving MLD being a TXOP responder on the first link. For example, since the first and second links of the non-AP receiving MLD are non-STR link pairs and the STA operating on the first link as one of the STR link pairs is a TXOP responder, the STA operating on the second link as the other link of the non-STR link pair does not send a CTS even if it receives an RTS.

Even if an RTS is received, the receiving MLD will not respond with a CTS (intentionally), since the CTS response may cause interference to the reception of the first PPDU on the first link. That is, although the receiving MLD may send a CTS upon receiving an RTS on the second link, since the first PPDU is being received on the first link, a CTS is not sent based thereon.

The receiving MLD may receive a second PPDU including second data on a second link (S3050). For example, the receiving MLD may receive the second PPDU on the second link despite not sending the CTS.

For example, the receiving MLD may be a non-Simultaneous Transmission and Reception (STR) MLD in which transmission or reception cannot be performed in one of the first link and the second link while reception or transmission is performed on the other of the first link and the second link.

For example, the receiving MLD may send an Acknowledgement (ACK) for the first PPDU on the first link and may send an ACK for the second PPDU on the second link.

For example, the first link and the second link may be non-STR sets of links in which reception or transmission is performed on one of the links while transmission or reception is not performed in the other link.

For example, the receiving MLD may transmit information related to Simultaneous Transmit and Receive (STR) capabilities of the first link and the second link. This capability information transfer may be performed, for example, in an association operation. That is, the capability transmission may be performed before the PPDU transmission.

Fig. 31 illustrates an embodiment of an operation of transmitting an MLD.

Referring to fig. 31, a transmitting MLD may include a first station and a second Station (STA). A first STA may operate on a first link and a second STA may operate on a second link.

Transmitting the MLD may transmit a second RTS frame on the first link (S3110).

The transmitting MLD may receive a CTS frame for a second RTS frame on the first link (S3120).

The transmitting MLD may transmit a first Physical Protocol Data Unit (PPDU) including first data on a first link (S3130).

The transmitting MLD may transmit a first Request To Send (RTS) frame on the second link to the receiving MLD while receiving the first PPDU on the first link (S1040). Based on the first PPDU being received on the first link, the receiving MLD may skip a Clear To Send (CTS) frame transmission for the first RTS frame.

Even if an RTS is received, the receiving MLD will not respond with a CTS (intentionally), since the CTS response may cause interference to the reception of the first PPDU on the first link. That is, although the receiving MLD may send a CTS upon receiving an RTS on the second link, since the first PPDU is being received on the first link, a CTS is not sent based thereon. For example, since the receiving MLD is the recipient of a PPDU sent by the transmitting MLD that has obtained a TXOP on the first link (i.e., since it is a TXOP responder), a CTS is not sent even if an RTS is received on the second link. That is, based on the receiving MLD being a TXOP responder on the first link, the receiving MLD will not send a CTS even if an RTS is received on the second link. For example, since the first and second links on which the non-AP receives the MLD are non-STR link pairs and the STA operating on the first link that is one of the STR link pairs is a TXOP responder, the STA operating on the second link that is the other link of the non-STR link pair does not send a CTS even if it receives an RTS.

For example, since the STA operating on the first link that transmits the MLD is the TXOP owner, the STA operating in the first link that receives the MLD is the TXOP responder. Thus, based on the STA operating on the first link receiving the MLD being a TXOP responder, the transmitting MLD may transmit a PPDU on the second link even if a CTS is not received on the second link. That is, based on the STA operating on the first link that transmits the MLD being the TXOP owner, the transmitting MLD may transmit the PPDU on the second link even if the CTS is not received on the second link.

The transmitting MLD may transmit a second PPDU including second data to the receiving MLD on a second link (S3150). For example, the transmitting MLD may transmit the second PPDU on the second link despite not receiving the CTS.

For example, the receiving MLD may be a non-Simultaneous Transmission and Reception (STR) MLD in which transmission or reception cannot be performed in one of the first link and the second link while reception or transmission is performed on the other of the first link and the second link.

For example, the receiving MLD may send an Acknowledgement (ACK) for the first PPDU on the first link and may send an ACK for the second PPDU on the second link.

For example, the first link and the second link may be non-STR sets of links in which reception or transmission is performed on one of the links while transmission or reception is not performed in the other link.

For example, the receiving MLD may transmit information related to Simultaneous Transmit and Receive (STR) capabilities of the first link and the second link. This capability information transfer may be performed, for example, in an association operation. That is, the capability transmission may be performed before the PPDU transmission.

Some of the detailed steps shown in the examples of fig. 30 and 31 may not be necessary steps and may be omitted. Other steps may be added in addition to those shown in fig. 30 and 31, and the order of the steps may vary. Some of the above steps may have independent technical meanings.

The above-described technical features of the present specification can be applied to various apparatuses and methods. For example, the above-described technical features of the present description may be performed/supported by the apparatus of fig. 1 and/or fig. 19. For example, the above-described technical features of the present specification may be applied to only a part of fig. 1 and/or fig. 19. For example, the above technical features of the present specification may be implemented based on the processing chips 114 and 124 of fig. 1, or may be implemented based on the processors 111 and 121 and the memories 112 and 122 of fig. 1, or may be implemented based on the processor 610 and the memory 620 of fig. 19. For example, in an apparatus of receiving a multi-link device (MLD) of the present specification, receiving the MLD may include: a first Station (STA); and a second STA. A first STA may operate on a first link and a second STA may operate on a second link. The apparatus may include: a memory; and a processor operatively coupled to the memory. The first STA may be a transmission opportunity (TXOP) responder. The processor may be configured to: receiving a first Request To Send (RTS) frame on a second link; skipping a clear-to-send (CTS) frame transmission of the first RTS frame based on the first STA being a TXOP responder; and receiving a Physical Protocol Data Unit (PPDU) on the second link.

The technical features of the present specification may be implemented based on a Computer Readable Medium (CRM). For example, a CRM presented herein is at least one computer-readable medium comprising instructions executable by at least one processor of a receiving multi-link device (MLD) of a Wireless Local Area Network (WLAN) system. The receiving MLD may include a first station and a second Station (STA). A first STA may operate on a first link and a second STA may operate on a second link. The first STA may be a transmission opportunity (TXOP) responder. The instructions may perform the following operations: receiving a first Request To Send (RTS) frame on a second link; skipping a clear-to-send (CTS) frame transmission of the first RTS frame based on the first STA being a TXOP responder; and receiving a Physical Protocol Data Unit (PPDU) on the second link.

The instructions stored in the CRM of this specification are executable by at least one processor. The at least one processor associated with the CRM of this specification may be processors 111 and 121 or processing chips 114 and 124 of fig. 1 or processor 610 of fig. 19. Further, the CRM of this specification may be the memories 112 and 122 of fig. 1 or the memory 620 of fig. 19 or a separate external memory/storage medium/disk or the like.

The above-described features of the present description are applicable to various applications or business models. For example, the above technical features may be applied to wireless communication of an Artificial Intelligence (AI) -enabled device.

Artificial intelligence refers to the field of research on artificial intelligence or methods of creating artificial intelligence, and machine learning refers to the field of research on methods of defining and solving various problems in the field of artificial intelligence. Machine learning is also defined as an algorithm that improves operational performance through a steady experience of operation.

An Artificial Neural Network (ANN) is a model used in machine learning, and may refer to an overall problem solving model including artificial neurons (nodes) that form a network by combining synapses. The artificial neural network may be defined by a connection pattern between neurons of different layers, a learning process of updating model parameters, and an activation function of generating an output value.

The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer includes one or more neurons, and an artificial neural network may include synapses connecting the neurons. In an artificial neural network, individual neurons may output a function value of an activation function of an input signal, a weight, and a deviation input through synapses.

The model parameters refer to parameters determined by learning, and include the weight of synaptic connections and the deviation of neurons. The hyper-parameters refer to parameters set before learning in a machine learning algorithm, and include a learning rate, an iteration number, a mini-batch size, and an initialization function.

Learning an artificial neural network may aim at determining model parameters for minimizing a loss function. The loss function may be used as an index to determine the optimization model parameters in learning the artificial neural network.

Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning.

Supervised learning refers to a method of training an artificial neural network given labels for training data, where the labels may indicate correct answers (or result values) that the artificial neural network needs to infer when the training data is input to the artificial neural network. Unsupervised learning may refer to a method of training an artificial neural network without giving labels to the training data. Reinforcement learning may refer to a training method defined in a training environment for an agent to select an action or sequence of actions to maximize the cumulative reward at various states.

Machine learning implemented with a Deep Neural Network (DNN) including a plurality of hidden layers among artificial neural networks is called deep learning, and deep learning is part of machine learning. Hereinafter, machine learning is explained as including deep learning.

The technical characteristics can be applied to the wireless communication of the robot.

A robot may refer to a machine that automatically processes or operates a given task in its own capacity. Specifically, a robot having a function of recognizing an environment and autonomously making a judgment to perform an operation may be referred to as an intelligent robot.

Robots may be classified into industrial, medical, household, military robots, etc. according to use or field. The robot may include actuators or drives that include motors to perform various physical operations (e.g., moving a robot joint). In addition, the mobile robot may include wheels, brakes, propellers, etc. in the drives to travel on the ground or fly in the air by the drives.

The above technical features can be applied to an apparatus supporting augmented reality.

Augmented reality refers collectively to Virtual Reality (VR), augmented Reality (AR), and Mixed Reality (MR). VR technology is computer graphics technology that provides a real world object and background only in a CG image, AR technology is computer graphics technology that provides a virtual CG image on a real object image, and MR technology is computer graphics technology that provides a virtual object mixed and combined with a real world.

MR technology is similar to AR technology in that real objects and virtual objects are displayed together. However, the virtual object is used as a complement to the real object in the AR technique, whereas the virtual object and the real object are used as an equivalent state in the MR technique.

XR technology may be applied to Head Mounted Displays (HMDs), head Up Displays (HUDs), mobile phones, tablet PCs, laptop computers, desktop computers, TVs, digital signage, and the like. Devices that employ XR technology may be referred to as XR devices.

The claims recited in this specification may be combined in various ways. For example, the technical features of the method claims of the present specification may be combined to realize an apparatus, and the technical features of the apparatus claims of the present specification may be combined to realize by a method. In addition, technical features of method claims and technical features of apparatus claims of the present description may be combined to be implemented as an apparatus, and technical features of method claims and technical features of apparatus claims of the present description may be combined to be implemented by a method.

Claims (16)

1. A method performed in a receiving multi-link device MLD of a wireless local area network WLAN system, the method comprising the steps of:

wherein the receiving MLD comprises a first Station (STA) operating on a first link and a second STA operating on a second link,

wherein the first STA is a transmission opportunity (TXOP) responder and

receiving a first Request To Send (RTS) frame on the second link;

skipping Clear To Send (CTS) frame transmission for the first RTS frame based on the first STA being the TXOP responder; and

receiving a Physical Protocol Data Unit (PPDU) on the second link.

2. The method of claim 1, wherein the receive MLD is a non-simultaneous transmit and receive STR MLD where transmission or reception cannot be performed in one of the first link and the second link while reception or transmission is performed on the other of the first link and the second link.

3. The method of claim 1, further comprising, prior to receiving the first RTS frame on the second link:

receiving a second RTS frame on the first link; and

transmitting a CTS frame for the second RTS frame on the first link.

4. The method of claim 1, further comprising the steps of: transmitting an acknowledgement ACK for the PPDU on the second link.

5. The method of claim 1, wherein the first link and the second link are sets of non-STR links in which reception or transmission is not performed in one of the links while reception or transmission is performed in the other link.

6. The method of claim 1, further comprising the steps of: transmitting information related to simultaneous transmission and reception of STR capabilities of the first link and the second link.

7. A receiving multi-link device, MLD, for use in a wireless local area network, WLAN, system, the receiving MLD comprising:

a first Station (STA); and

the second STA is provided with a second STA,

wherein the first STA operates on a first link and the second STA operates on a second link,

wherein the first STA is a transmission opportunity (TXOP) responder and

wherein the receiving MLD is arranged to:

receiving a first request-to-send (RTS) frame on the second link;

skipping clear-to-send (CTS) frame transmission for the first RTS frame based on the first STA being the TXOP responder; and is provided with

Receiving a Physical Protocol Data Unit (PPDU) on the second link.

8. The receiving MLD of claim 7, wherein the receiving MLD is a non-simultaneous transmission and reception STR MLD in which transmission or reception cannot be performed in one of the first link and the second link while reception or transmission is performed on the other of the first link and the second link.

9. The receiving MLD of claim 7, wherein prior to receiving the first RTS frame on the second link, the receiving MLD is further configured to:

receiving a second RTS frame on the first link; and is

Transmitting a CTS frame for the second RTS frame on the first link.

10. The receiving MLD as claimed in claim 7, wherein the receiving MLD is further configured to transmit an acknowledgement ACK for the PPDU on the second link.

11. The receiving MLD as recited in claim 7, wherein the first link and the second link are non-STR link sets that cannot perform transmission or reception in one of the links while performing reception or transmission on the other link.

12. The receiving MLD of claim 7, further configured to transmit information related to simultaneous transmission and reception STR capabilities of the first link and the second link.

13. A method performed in a transmitting multi-link device, MLD, of a wireless local area network, WLAN, system, the method comprising the steps of:

wherein the transmitting MLD includes a first STA operating on a first link and a second STA operating on a second link,

wherein the first STA is a transmission opportunity TXOP owner, and

sending a Request To Send (RTS) frame on the second link;

transmitting a Physical Protocol Data Unit (PPDU) on the second link even if a Clear To Send (CTS) frame is not received for the RTS frame based on the first STA being the TXOP owner.

14. A transmitting multi-link device MLD for use in a wireless local area network, WLAN, system, the transmitting MLD comprising:

a first Station (STA); and

the second STA may be capable of performing a second STA,

wherein the first STA is a transmission opportunity TXOP owner, and

wherein the transmit MLD is configured to:

sending a Request To Send (RTS) frame on a second link;

transmitting a Physical Protocol Data Unit (PPDU) on the second link based on the first STA being the TXOP owner even if a Clear To Send (CTS) frame is not received for the RTS frame.

15. At least one computer-readable medium comprising instructions for execution by at least one processor of a receiving multi-link device (MLD) of a Wireless Local Area Network (WLAN) system to:

wherein the receiving MLD comprises a first Station (STA) operating on a first link and a second STA operating on a second link,

wherein the first STA is a transmission opportunity (TXOP) responder and

wherein the instructions perform the following operations:

receiving a first request-to-send (RTS) frame on the second link;

skipping clear-to-send (CTS) frame transmission for the first RTS frame based on the first STA being the TXOP responder; and

receiving a Physical Protocol Data Unit (PPDU) on the second link.

16. An apparatus for receiving a multi-link device (MLD) on a Wireless Local Area Network (WLAN) system,

wherein the receiving MLD comprises a first Station (STA) and a second STA, the first STA operating on a first link and the second STA operating on a second link, and

wherein the apparatus comprises:

a memory; and

a processor operatively coupled to the memory,

wherein the first STA is a transmission opportunity (TXOP) responder and

wherein the processor is arranged to:

receiving a first request-to-send (RTS) frame on the second link;

skipping clear-to-send (CTS) frame transmission for the first RTS frame based on the first STA being the TXOP responder; and is provided with

Receiving a Physical Protocol Data Unit (PPDU) on the second link.

Images